Validate Repeater current row value with previous row value in ASP.Net

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPageInnernew.Master" AutoEventWireup="true" CodeBehind="TT_PeriodSetting.aspx.cs" Inherits="eCareERP.TimeTable.TT_PeriodSetting" %>

<%@ Register Assembly="CustomButton" Namespace="Custom.eCareERP" TagPrefix="cc1" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
     <script type="text/javascript">
        function OnChange() {
            $("#showpopup").dialog({
                title: 'Set Max Period',
                width: 300,
                height: 150,
                position: ['center', 25],
                closeOnEscape: true,
                modal: false,
                zIndex: 1000,
                stack: false
                //open: function (event, ui) { $(".ui-dialog-titlebar-close").hide(); }
            }).parent().appendTo($("form:first"));
        }
    </script>

    <div id="page-wrapper1">
        <div class="white-box">
            <%--<h3 class="text-center box-title" >Period Time Setting </h3>--%>

            <div class="row button-box m-t-10 text-center">

                <asp:LinkButton ID="btnUpdatePeriod" Text="Update" OnClick="btnUpdatePeriod_Click" CssClass="global btn btn-outline btn-info  " runat="server" CausesValidation="False"  ><i class="mdi mdi-update"></i> Update</asp:LinkButton>
            </div>


            <%--    <div id="showpopup"style="width: 200px; display: none; z-index: 1001;">
            <fspl:eCareTextBox ID="txtperiod" text="" TextType="Numeric" MaxValue="90" runat="server" />
              <asp:Button ID="BtnSetPeriod" Text="Set Period" OnClick="BtnSetPeriod_Click" CssClass="global" runat="server"  CausesValidation="False"/>            
         </div> --%>

            <div class="table table-responsive" id="myTablePeriod">

                <asp:UpdatePanel ID="upnl1" runat="server">
                    <ContentTemplate>
                        <%-- <table border='0' cellspacing='3' class='display' id='example1' cellpadding='3' width='90%' style="width: 100%">--%>
                        <table id="myTable_k" class="table table-striped table-bordered">
                            <thead>
                                <tr>
                                    <th>SNo.</th>
                                    <th>Period</th>
                                    <%--   <th style="width:300px"><img src="../Images/modify-icon.png" style="width:auto;height:16px"  onclick="OnChange()" />Time</th>--%>
                                    <th>Time</th>
                                    <th style="display:none">
                                        <div class="checkbox checkbox-info m-0">
                                            <asp:CheckBox ID="chkaddall" runat="server" />
                                            <label class="col-md-12 "><strong>Set</strong>    </label>
                                        </div>
                                    </th>
                                </tr>
                            </thead>
                            <tbody>
                                <asp:UpdatePanel ID="up1" runat="server" UpdateMode="Always">
                                    <ContentTemplate>
                                        <asp:Repeater ID="rpt_TeacherDetails" runat="server">
                                            <ItemTemplate>
                                                <tr id="ItemRow2">
                                                    <td><%# Container.ItemIndex + 1 %></td>
                                                    <td>
                                                        <asp:Label ID="lblPeriods" runat="server" Text='<%# Eval("Periods") %>' />
                                                    </td>


                                                    <td>
                                                        <%--<fspl:eCareTextBox ID="txtTime"  runat="server" type="number" TextType="Numeric" MinValue="5" MaxValue="99" SetWidth="70" Text='<%# Eval("Time") %>'  Required="true" />  --%>
                                                        <%--<fspl:eCareTextBox ID="txtTime"  runat="server" TextType=""  SetWidth="100" Text='<%# Eval("Time") %>'  Required="true" />--%>
                                                        <asp:TextBox ID="txtTime" CssClass="form-control  input-sm" runat="server" Text='<%# Eval("Time") %>'></asp:TextBox>
                                                        <%--  <asp:RegularExpressionValidator ID="txtTimevalidate" runat="server" ControlToValidate="txtTime" 
                                                ValidationExpression="^(([0]?[1-9])|([1][0-2])):(([0-5][0-9])|([1-9])) [AP][M]$" ErrorMessage="Invalid Format" >                                              
                                            </asp:RegularExpressionValidator>--%>
                                                    </td>

                                                    <td style=" display:none">
                                                        <div class="checkbox checkbox-info m-0">
                                                            <asp:CheckBox ID="chkstatus" Text=" " runat="server" Checked='<%# Eval("Status").ToString() == "True" %>' Required="true" Visible="false" />
                                                        </div>
                                                    </td>
                                                </tr>
                                            </ItemTemplate>
                                        </asp:Repeater>
                                    </ContentTemplate>
                                </asp:UpdatePanel>

                            </tbody>

                        </table>
                    </ContentTemplate>

                </asp:UpdatePanel>

            </div>


        </div>
    </div>



    <script>
        //$(document).ready(function () {
        //    var $dataContainer = $('.table');
        //    oTable = $dataContainer.find('#myTable').dataTable({
        //        "bJQueryUI": true,
        //        "aoColumnDefs": [
        //        {
        //            "bSortable": false,
        //            "aTargets": [3] // <-- gets last column and turns off sorting
        //        }
        //        ],
        //        "bPaginate": false,
        //        "bFilter": true,
        //        "sPaginationType": "full_numbers",
        //        "sDom": '<""f>t<"F"lp>'
        //    })
        //});

        $(document).ready(function () {
            debugger
            var $dataContainer = $('.table');
            oTable = $dataContainer.find('#myTablePeriod').dataTable({
                "bJQueryUI": true,
                "aoColumnDefs": [
                                {
                                    "bSortable": false,
                                    "aTargets": [2, 3] // <-- gets last column and turns off sorting
                                }
                ],

                "bPaginate": false,
                "bFilter": true,
                "bDestroy": true,
                "sPaginationType": "full_numbers",
                "sDom": '<""f>t<"F"lp>'
            })


        });


        $(function () {
            $("#myTablePeriod [id*=chkaddall]").click(function () {
                if ($(this).is(":checked")) {
                    $("#myTablePeriod [id*=chkstatus]").prop("checked", "checked");
                } else {
                    $("#myTablePeriod [id*=chkstatus]").removeAttr("checked");
                }
            });
            $("#myTablePeriod [id*=chkstatus]").click(function () {
                if ($("#myTablePeriod [id*=chkstatus]").length == $("#myTablePeriod [id*=chkstatus]:checked").length) {
                    $("#myTablePeriod [id*=chkaddall]").prop("checked", "checked");
                } else {
                    $("#myTablePeriod [id*=chkaddall]").removeAttr("checked");
                }
            });
        });

    </script>
</asp:Content>