By refreshing gridview using timer, modal popup is automatically closing - asp.net

Question

Am using a modal pop for a grid view column where the grid view is set with timer.
<asp:UpdatePanel ID="GridPanel" runat="server">
<ContentTemplate>
<asp:Timer ID="autorefresh" runat="server" Interval="5000" />
<asp:GridView ID="SigmaGrid" runat="server" AutoGenerateColumns="False"
onrowcommand="SigmaGrid_RowCommand" CssClass="mGrid" PagerStyle-CssClass="pgr"
AlternatingRowStyle-CssClass="alt" AllowPaging="True"
onpageindexchanging="SigmaGrid_PageIndexChanging">
<AlternatingRowStyle CssClass="alt" />
<PagerStyle />
<Columns>
<asp:TemplateField HeaderText="FirstName" SortExpression="FirstName">
<ItemTemplate>
<asp:LinkButton ID="FirstName" runat="server" Text='<% # Eval("FirstName") %>' CommandName="Select"></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<PagerStyle CssClass="pgr" />
</asp:GridView>
<asp:Panel ID="DtlsPanel" runat="server" BackColor="White" Height="400" Width="500px" >
<table style="border: Solid 3px #626262; width: 100%; height: 100%"
cellpadding="0" cellspacing="0">
<tr style="background-color: #626262">
<td colspan="2" style="height: 10%; color: White; font-weight: bold; font-size: larger"
align="center">
Records
</td>
</tr>
<tr>
<td style="color: Black">
First Name:
</td>
<td align="center" style="color: Black">
<asp:Label ID="FNamelbl2" runat="server"></asp:Label>
</td>
</tr>
</table>
</asp:Panel>
<asp:Button ID="btnPopUp" runat="server" Style="display: none" />
<asp:ModalPopupExtender ID="DetailsPopUp1" runat="server" BackgroundCssClass="modalBackground"
TargetControlID="btnPopUp" PopupControlID="DtlsPanel" CancelControlID="btnCancel"
PopupDragHandleControlID="PopupHeader">
</asp:ModalPopupExtender>
</ContentTemplate>
</asp:UpdatePanel>
Code
protected void SigmaGrid_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "Select")
{
LinkButton FirstName = (LinkButton)e.CommandSource;
GridViewRow row = (GridViewRow)FirstName.NamingContainer;
FNamelbl2.Text = FirstName.Text;
this.DetailsPopUp1.Show();
}
}
Problem
Whne i click on firstname colunn i get a pop up which displays the details of a row.. As i have used timer gridview is refreshed and pop up is automatically closing.

Answer 1

If you're using a ModalPopupExtender with postbacks, you should ensure in codebehind that the popup will be shown. Therefore you can use it's method Show.
For example in the page's or UserControl's PreRender:
C#
protected void Page_PreRender(object sender, System.EventArgs e)
{
if (this.Visible) {
this.DetailsPopUp1.Show();
}
}
VB.NET
Private Sub Page_PreRender(sender As Object, e As System.EventArgs) Handles Me.PreRender
If Me.Visible Then
Me.DetailsPopUp1.Show()
End If
End Sub