Pass value from Popup window to main window using JavaScript in ASP.Net

Hi Dharmendar

It is my Parent window Html

<%@ Page Title="" Language="VB" MasterPageFile="~/inc/Site.master" AutoEventWireup="false" CodeFile="Purchase_Inv_add.aspx.vb" Inherits="mod_Sales_Dept_Purchase_Inv_add" %>
<%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="asp" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">

       <script type="text/javascript">
           var popup;
           function SelectName() {
               popup = window.open("ProductSearch.aspx", "Popup", "width=700,height=400");
               popup.focus();
               return false
           }
   </script>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<h4 class="box-title"><asp:Label ID="lblaction" runat="server"></asp:Label></h4>

<asp:UpdatePanel id="UpdatePanel1" runat="server">
    <ContentTemplate>
        <fieldset>
            <div class="row">
                <div class="col-lg-1">
                    <asp:Label ID="Label2" runat="server" Text="Doc No" Visible="true"></asp:Label>
                    <asp:TextBox ID="txtDocNo" runat="server" CssClass="form-control cbo" Enabled="false" Visible="true"></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label1" runat="server" Text="Doc Date" Visible="true"></asp:Label>
                    <asp:TextBox ID="txtDocDate" runat="server" CssClass="form-control cbo" Enabled="true" Visible="true"></asp:TextBox>
                    <asp:CalendarExtender ID="txtDocDate_CalendarExtender" runat="server" Enabled="True" TargetControlID="txtDocDate" Format="dd-MM-yyyy">
                    </asp:CalendarExtender>
                </div>
               <div class="col-lg-1">
                    <asp:Label ID="Label3" runat="server" Text="ID" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtID" runat="server" CssClass="form-control cbo" Enabled="false" Visible="false" ></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label4" runat="server" Text="Type" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtType" runat="server" CssClass="form-control cbo" Enabled="false" Text="PI" Visible="false"></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label5" runat="server" Text="Currency" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtCurrCode" runat="server" CssClass="form-control cbo" Enabled="false" Text="RM" Visible="false" ></asp:TextBox>
                </div>
           </div>
<br />
<div class="row">
    <div class="col-lg-7">

        <div class="panel panel-primary">
            <div class="panel-heading"><h4 class="panel-title">Supplier Details</h4></div>
                <div class="panel-body"> 
                    <div class="row">
                        <div class="col-lg-2">
                            <asp:Label ID="Label8" runat="server" Text="Ac No"></asp:Label>
                            <asp:DropDownList ID="cboCode" runat="server" CssClass="form-control cbo" AutoPostBack="true" AppendDataBoundItems="true"></asp:DropDownList>
                        </div>
                        <div class="col-lg-3">
                            <asp:Label ID="Label9" runat="server" Text="Name"></asp:Label>
                            <asp:TextBox ID="txtName" runat="server" CssClass="form-control" Enabled="false"></asp:TextBox>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-lg-3">
                            <asp:Label ID="Label7" runat="server" Text="Supp Inv"></asp:Label>
                            <asp:TextBox ID="txtCustPO" runat="server" CssClass="form-control" Enabled="true" Width="150px"></asp:TextBox>
                        </div>

                        <div class="col-lg-3">
                            <asp:Label ID="Label6" runat="server" Text="Sales Persopn"></asp:Label>
                            <asp:DropDownList ID="cboSalesPerson" runat="server" CssClass="form-control" Width="150px"></asp:DropDownList>
                        </div>

                        <div class="col-lg-1">
                            <asp:Label ID="Label30" runat="server" Text="SaleType"></asp:Label>
                            <asp:TextBox ID="txtSalesType" runat="server" CssClass="form-control cbo" Enabled="false"></asp:TextBox>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-lg-3">
                            <asp:Label ID="Label10" runat="server" Text="Trans.Type"></asp:Label>
                            <asp:DropDownList ID="cboTransType" runat="server" CssClass="form-control" Width="150px" AppendDataBoundItems="true" ></asp:DropDownList>
                        </div>
                        <div class="col-lg-3">
                            <asp:Panel ID="Panel4" runat="server" DefaultButton="btnTransChg">
                                <asp:Label ID="Label11" runat="server" Text="Trans.Chg"></asp:Label>
                                <asp:TextBox ID="txtTransChg" runat="server" CssClass="form-control" Enabled="true" Width="150px"></asp:TextBox>
                                <asp:Button ID="btnTransChg" runat="server" style="display:none"/>
                            </asp:Panel>
                        </div>
                        <div class="col-lg-1">
                            <asp:Label ID="Label12" runat="server" Text="Trans.GST"></asp:Label>
                            <asp:TextBox ID="txtTransGST" runat="server" CssClass="form-control cbo" Enabled="false"></asp:TextBox>
                        </div>
                    </div>
                    <div class="row">
                      <div class="col-lg-2">
                            <asp:Label ID="Label33" runat="server" Text="Qty"></asp:Label>
                            <asp:TextBox ID="txtTotalQty" runat="server" CssClass="form-control cbo" Enabled="false"></asp:TextBox>
                        </div>
                        <div class="col-lg-2">
                            <asp:Label ID="Label31" runat="server" Text="Disc.Amt"></asp:Label>
                            <asp:TextBox ID="txtTotalDiscAmt" runat="server" CssClass="form-control cbo" Enabled="false"></asp:TextBox>
                        </div>
                        <div class="col-lg-2">
                            <asp:Label ID="Label15" runat="server" Text="GST.Amt"></asp:Label>
                            <asp:TextBox ID="txtTotalGSTR" runat="server" CssClass="form-control cbo" Enabled="false"></asp:TextBox>
                        </div>

                        <div class="col-lg-1">
                            <asp:Label ID="Label16" runat="server" Text="Nett"></asp:Label>
                            <asp:TextBox ID="txtTotalNETT" runat="server" CssClass="form-control cbo" Enabled="false"></asp:TextBox>
                        </div>
                   </div>
                    <div class="row">
                        <div class="col-lg-2">
                            <asp:Label ID="Label32" runat="server" Text="GrandTotal" Visible="true"></asp:Label>
                            <asp:TextBox ID="txtOverALLTotal" runat="server" CssClass="form-control cbo" Enabled="false" Visible="true"></asp:TextBox>
                        </div>
 
                        <div class="col-lg-2">
                            <asp:Label ID="Label17" runat="server" Text="Status"></asp:Label>
                            <asp:DropDownList ID="cboStatus" runat="server" CssClass="form-control cbo"></asp:DropDownList>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-lg-1">
                            <asp:Label ID="Label14" runat="server" Text="Grand.Total" Visible="false"></asp:Label>
                            <asp:TextBox ID="txtGrandTotal" runat="server" CssClass="form-control cbo" Enabled="false" Visible="false"></asp:TextBox>
                        </div>
                        <div class="col-lg-1">
                            <asp:Label ID="Label13" runat="server" Text="Total" Visible="false"></asp:Label>
                            <asp:TextBox ID="txtTotal" runat="server" CssClass="form-control cbo" Enabled="false" Visible="false"></asp:TextBox>
                        </div>
                    </div>
             </div>
        </div>
    </div>
     <div class="col-lg-5">
        <div class="panel panel-primary">
            <div class="panel-heading"><h4 class="panel-title">Products Search</h4></div>
                <div class="panel-body"> 
                   <div class="row">
                      <div class="col-lg-3">
                          <asp:Panel ID="Panel5" runat="server" DefaultButton="btnSearch">
                            <asp:TextBox ID="txtSearch" runat="server" CssClass="form-control"></asp:TextBox>
                            <asp:Button ID="btnSearch" runat="server" Text="..." style="display:none"/>
                          </asp:Panel>
                           </div>
                       </div>
                        <div class="grid_scroll grid_scroll_small">
                              <asp:GridView ID="GridView1" runat="server" CssClass="gridview" AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None" 
                                BorderWidth="1px" CellPadding="3" GridLines="Horizontal" PageSize="15" Font-Names="Calibri" Font-Size="Small">
                                <AlternatingRowStyle BackColor="#F7F7F7" />
                                <Columns>
                                    <asp:CommandField ShowSelectButton="True"><ItemStyle Width="50px" /></asp:CommandField>
                                    <asp:BoundField DataField="id" InsertVisible="False" ReadOnly="True" SortExpression="id" Visible="true" HeaderText="ID"/>
                                    <asp:BoundField DataField="itemid" HeaderText="Item Code"/>
                                    <asp:BoundField DataField="itemdes" HeaderText="Description"/>
        <%--                            <asp:BoundField DataField="Category" HeaderText="Category"/>
                                    <asp:BoundField DataField="uom" HeaderText="UOM"/>
                                    <asp:BoundField DataField="Suppprice" HeaderText="SuppPrice"/>
                                    <asp:BoundField DataField="taxcode" HeaderText="Tax Code"/>--%>
                                </Columns>
                                <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
                                <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
                                <PagerStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Right" />
                                 <RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />
                                <SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
                                <SortedAscendingCellStyle BackColor="#F4F4FD" />
                                <SortedAscendingHeaderStyle BackColor="#5A4C9D" />
                                <SortedDescendingCellStyle BackColor="#D8D8F0" />
                                <SortedDescendingHeaderStyle BackColor="#3E3277" />
                            </asp:GridView>
                    </div>
                </div>

            </div>
         </div>
</div>
<div class="panel panel-info">
    <div class="panel-heading"><h4 class="panel-title">Item Details</h4></div>
        <div class="panel-body"> 
            <div class="row">
               
                <div class="col-lg-2">
                <asp:Panel ID="Panel1" runat="server" DefaultButton="btnSearchProdDetails">
                    
                    <asp:Label ID="Label18" runat="server" Text="Item ID"></asp:Label>
                    <asp:TextBox ID="txtItemID" runat="server" CssClass="form-control" Enabled="true" Width="180px" ClientIDMode="Static"></asp:TextBox>
                    <asp:Button ID="btnSearchProdDetails" runat="server" Text="." Height="1px" Width="1px"  Visible="true" BorderStyle="None" BackColor="window"/>
                
                </asp:Panel>                   
                </div>
 
                <div class="col-lg-3">
                    <asp:Label ID="Label19" runat="server" Text="Description"></asp:Label>
                    <asp:TextBox ID="txtItemDesc" runat="server" CssClass="form-control" Enabled="false" Width="270px"></asp:TextBox>
                    <asp:Button ID="btnItemDesSearch" runat="server" Text="Search" OnClientClick="SelectName();" Visible="false" />
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label21" runat="server" Text="Price"></asp:Label>
                    <asp:TextBox ID="txtPrice" runat="server" CssClass="form-control cbo" Enabled="false" Text="0.00"></asp:TextBox>
                </div>
                 
                    <div class="col-lg-1">
                    <asp:Panel ID="Panel2" runat="server" DefaultButton="btnCalc">
                        <asp:Label ID="Label22" runat="server" Text="Qty"></asp:Label>
                        <asp:TextBox ID="txtQty" runat="server" CssClass="form-control cbo" Enabled="true" ></asp:TextBox>
                         <asp:Button ID="btnCalc" runat="server" style="display:none"/>
                     </asp:Panel>
                    </div>
                
                <div class="col-lg-1">
                    <asp:Panel ID="Panel3" runat="server" DefaultButton="btnCalcDisc">
                        <asp:Label ID="Label23" runat="server" Text="Disc(%)"></asp:Label>
                        <asp:TextBox ID="txtDisc" runat="server"  CssClass="form-control cbo" Enabled="true" ></asp:TextBox>
                        <asp:Button ID="btnCalcDisc" runat="server" style="display:none"/>
                    </asp:Panel>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label25" runat="server" Text="Amount"></asp:Label>
                    <asp:TextBox ID="txtAmount" runat="server" CssClass="form-control cbo" Enabled="false" Text="0.00"></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label28" runat="server" Text="GST Amt"></asp:Label>
                    <asp:TextBox ID="txtGSTR" runat="server" CssClass="form-control cbo" Enabled="false" Text="0.00"></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label29" runat="server" Text="Amount"></asp:Label>
                    <asp:TextBox ID="txtNett" runat="server" CssClass="form-control cbo" Enabled="false" Text="0.00"></asp:TextBox>
                </div>
            </div>
            <div class="row">           
                <div class="col-lg-1">
                    <asp:Label ID="Label34" runat="server" Text="ExpiryDate"></asp:Label>
                    <asp:TextBox ID="txtExpiryDate" runat="server" CssClass="form-control cbo"></asp:TextBox>
                    <asp:CalendarExtender ID="txtExpiryDate_CalendarExtender" runat="server" Enabled="True" TargetControlID="txtExpiryDate" Format="dd-MM-yyyy">
                    </asp:CalendarExtender>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label41" runat="server" Text="." ></asp:Label>
                   <asp:Button CssClass="btn btn-primary" ID="btnGridAdd" runat="server" Text="Add (+)"  Height="30px"/>
                </div>
       
           </div>     
            <div class="row">
                <div class="col-lg-1">
                    <asp:Label ID="Label20" runat="server" Text="UOM" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtUOM" runat="server" CssClass="form-control cbo" Enabled="false" Visible="false"></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label24" runat="server" Text="Disc Amt" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtDiscAmt" runat="server" CssClass="form-control cbo" Enabled="false" Visible="false"></asp:TextBox>
                </div>

                <div class="col-lg-1">
                    <asp:Label ID="Label26" runat="server" Text="GST(%)" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtGSTP" runat="server" CssClass="form-control cbo" Enabled="false" Visible="false"></asp:TextBox>
                </div>
                <div class="col-lg-1">
                    <asp:Label ID="Label27" runat="server" Text="Tax Code" Visible="false"></asp:Label>
                    <asp:TextBox ID="txtTaxCode" runat="server" CssClass="form-control cbo" Enabled="false" Width="70px" Visible="false"></asp:TextBox>
                </div>
            </div>                   
        </div>
 </div>        

   <div class="box-footer">
        <asp:Button ID="btnSave" runat="server" Text="Submit" CssClass="btn btn-primary" />
        <asp:Button ID="btnPrint" runat="server" Text="Print" CssClass="btn btn-primary" />
        <asp:Button ID="btnBack" runat="server" Text="Back" CssClass="btn btn-primary" />
    </div>
<%--        </fieldset>
    </ContentTemplate>
</asp:UpdatePanel>



 <asp:UpdatePanel id="UpdatePanel2" runat="server">
    <ContentTemplate>
        <fieldset>--%>
            <div class="well well-sm">
                <div class="row">
                    <div class="col-lg-12">
                        <asp:GridView ID="gv" runat="server" AutoGenerateColumns="False" BackColor="White" BorderColor="#999999" BorderStyle="Solid" 
                         BorderWidth="1px" CellPadding="3" Width="100%" ForeColor="Black" GridLines="Vertical" CssClass="gridview">
                         <AlternatingRowStyle BackColor="#CCCCCC" />
                         <Columns>
                             <asp:CommandField ShowSelectButton="true" />
<%--                             <asp:CommandField ShowEditButton="true" />--%>
                             
                            <asp:TemplateField HeaderText = "SNo" ItemStyle-Width="10">
                                <ItemTemplate>
                                    <asp:Label ID="lblRowNumber" Text='<%# Container.DataItemIndex + 1 %>' runat="server" />
                                </ItemTemplate>
                            </asp:TemplateField>

                             <asp:BoundField DataField="itemid" HeaderText="Item ID" />
                             <asp:BoundField DataField="itemdes" HeaderText="Description" />
                             <asp:BoundField DataField="uom" HeaderText="UOM" />

                             <asp:BoundField DataField="price" HeaderText="Price" ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="qty" HeaderText="Qty"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="disc" HeaderText="Disc(%)"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="discAmt" HeaderText="Disc Amt"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="amount" HeaderText="Amount"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="gstp" HeaderText="GSTP"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="gstr" HeaderText="GSTR"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="nett" HeaderText="Nett"  ><ItemStyle HorizontalAlign="Right" /></asp:BoundField>
                             <asp:BoundField DataField="taxcode" HeaderText="TaxCode" />
                             <asp:BoundField DataField="expirydate" HeaderText="Expiry Date" />

                             <asp:CommandField ShowDeleteButton="true" />

                         </Columns>
                         <FooterStyle BackColor="#CCCCCC" />
                         <HeaderStyle BackColor="Black" Font-Bold="True" ForeColor="White" />
                         <PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
                         <SelectedRowStyle BackColor="#000099" Font-Bold="True" ForeColor="White" />
                         <SortedAscendingCellStyle BackColor="#F1F1F1" />
                         <SortedAscendingHeaderStyle BackColor="#808080" />
                         <SortedDescendingCellStyle BackColor="#CAC9C9" />
                         <SortedDescendingHeaderStyle BackColor="#383838" />
                     </asp:GridView>   
                </div>
            </div>
           </div>
        </fieldset>
    </ContentTemplate>
</asp:UpdatePanel>

</asp:Content>

It is my Popup windows html

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="ProductSearch.aspx.vb" Inherits="mod_Purchase_Dept_ProductSearch" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Product Search</title>

</head>
<body>
    <form id="form1" runat="server">
        <asp:Label ID="Label1" runat="server" Text="Select Item Name"></asp:Label>
        <asp:TextBox ID="txtSearch" runat="server"></asp:TextBox>
        <asp:Button ID="btnSearch" runat="server" Text="Search" />
        <asp:TextBox ID="txtItemName" runat="server"></asp:TextBox>
        <asp:Button ID="btnSelectItem" runat="server" Text="select Item" OnClientClick="return SelectName()"  />

    <div>

       <script type="text/javascript">
           function SelectName() {
               if (window.opener != null && !window.opener.closed) {
                   var form = window.opener.document.getElementsByTagName("form")[0];
                   var txtName = GetElement(form, "span", "txtItemID");
                   txtName.innerHTML = document.getElementById("txtItemName").value;
               }
               //return false;
               window.close();
           }
           function GetElement(parent, tagName, id) {
               var elem = parent.getElementsByTagName(tagName);
               for (var i = 0; i < parent.getElementsByTagName(tagName).length; i++) {
                   if (elem[i].id.indexOf(id) != -1) {
                       return elem[i];
                   }
               }
               return null;
           }
    </script>




    <br />
     <asp:GridView ID="GridView1" runat="server" CssClass="gridview" AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None" 
        BorderWidth="1px" CellPadding="3" GridLines="Horizontal" PageSize="15" Font-Names="Calibri" Font-Size="Small">
        <AlternatingRowStyle BackColor="#F7F7F7" />
        <Columns>
<%--                <asp:TemplateField>
                    <AlternatingItemTemplate>
                        <asp:Button ID="btnSelect" runat="server" Text="Select" />
                    </AlternatingItemTemplate>
                    <ItemTemplate>
                        <asp:Button ID="btnSelect" runat="server" Text="Select" />
                    </ItemTemplate>
                </asp:TemplateField>--%>
            <asp:CommandField ShowSelectButton="True"><ItemStyle Width="50px" /></asp:CommandField>
            <asp:BoundField DataField="id" InsertVisible="False" ReadOnly="True" SortExpression="id" Visible="true" HeaderText="ID"/>
            <asp:BoundField DataField="itemid" HeaderText="Item Code"/>
            <asp:BoundField DataField="itemdes" HeaderText="Description"/>
            <asp:BoundField DataField="Category" HeaderText="Category"/>
            <asp:BoundField DataField="uom" HeaderText="UOM"/>
            <asp:BoundField DataField="Suppprice" HeaderText="SuppPrice"/>
            <asp:BoundField DataField="taxcode" HeaderText="Tax Code"/>
            

        </Columns>
        <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
        <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
        <PagerStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Right" />
         <RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />
        <SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
        <SortedAscendingCellStyle BackColor="#F4F4FD" />
        <SortedAscendingHeaderStyle BackColor="#5A4C9D" />
        <SortedDescendingCellStyle BackColor="#D8D8F0" />
        <SortedDescendingHeaderStyle BackColor="#3E3277" />
    </asp:GridView>
    
    </div>
   </form>
</body>
</html>

Pls advice.

Thank you

Maideen

Hi maideen,

I have modified my previous reply with master page and the code is working as per the article. Refer the below link.

http://www.aspforums.net/Threads/409198/Passing-value-from-Popup-window-to-main-windows/Replies/2#Replies

Thank you very much. 

My Problem is once click the button in popup window, the selected value does not display in asp:text box in parent window (with Master Page)

But It can display result in asp:label in parent window. If I change 

var txtName = GetElement(form, "span", "txtItemID"); to 

var txtName = GetElement(form, "span", "lblItem"); 

Popup window disappeared and select value is displaying in asp:lblItem in Parent window.

Pls advice me.

Thank you

Maideen

Hi maideen,

Change the function like below. What you are doing wrong is you are trying to assign tagName as span but the tagName is input and assign the value to the textbox with .value not with .innerHTML

function SelectName() {
    if (window.opener != null && !window.opener.closed) {
        var form = window.opener.document.getElementsByTagName("form")[0];
        var txtName = GetElement(form, "input", "txtItemID");
        txtName.value = document.getElementById("txtName").value;
    }
    window.close();
}
function GetElement(parent, tagName, id) {
    var elem = parent.getElementsByTagName(tagName);
    for (var i = 0; i < parent.getElementsByTagName(tagName).length; i++) {
        if (elem[i].id.indexOf(id) != -1) {
            return elem[i];
        }
    }
    return null;