[Solved] ASP.Net Button Click event inside jQuery Modal Popup is not working

The jQuery dialog box is rendered outside the form.

So you need to re-add the element to the form.

HTML

<div id="dialog" style="display: none">
    This is a simple popup
    <br />
    <br />
    <asp:TextBox ID="txt_name" runat="server"></asp:TextBox>
    <asp:Button runat="server" Text="Submit" OnClick="OnSubmit" />
</div>
<asp:Button ID="btnPopup" runat="server" Text="Show Popup" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.24/themes/smoothness/jquery-ui.css" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.24/jquery-ui.min.js"></script>
<script type="text/javascript">
    $(function () {
        $("[id*=btnPopup]").on("click", function () {
            $("#dialog").dialog({
                title: "jQuery Dialog Popup",
                buttons: {
                    Close: function () {
                        $(this).dialog('close');
                    }
                },
                modal: true,
                open: function (type, data) {
                    $(this).parent().appendTo("form");
                }
            });
            return false;
        });
    });
</script>

Code

C#

protected void OnSubmit(object sender, EventArgs e)
{
    ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('" + txt_name.Text + "');", true);
}

VB.Net

Protected Sub OnSubmit(ByVal sender As Object, ByVal e As EventArgs)
    ClientScript.RegisterClientScriptBlock(Me.GetType(), "alert", "alert('" & txt_name.Text & "');", True)
End Sub

Screenshot