asp:UpdatePanel ID="Panel1" runat="server">

    <ContentTemplate>

    <asp:GridView ID="grid1" runat="server">

      <Columns>

      <asp:TemplateField>

        <ItemTemplate>

        

        </ItemTemplate>

        <HeaderTemplate>

        <span onmouseup="MouseUp(this);">Test</span>

        </HeaderTemplate>

      </asp:TemplateField>

      </Columns>

    </asp:GridView>

    <asp:Button ID="b1" runat="server" OnClick="b1_Click" Text="" />

    </ContentTemplate>

    <Triggers>

    <asp:AsyncPostBackTrigger ControlID="b1" />

    </Triggers>

</asp:UpdatePanel>





protected void btnpb_Click(object sender, EventArgs e)

    {
    try

    {
// executiing a sql query for getting a condition depending on which teh control will be visible true/ fasle

if (reader["status"]=="A")
      div1.Visible = true;
else if (reader["status"]=="B")
  {     dropdown1.visible = true
populatedropdown();
}
else
{
   textbox1.Visible = true;
}


  

    }

    catch

    {

    }

    }

Javascript

<script type="text/javascript">

 

    function MouseUp(e) {
// this script will be executed wen the grid header cell is clicked
    document.getElementById('<b1').click();

    }

</script>


i have the above code

issues faced
1)the time to populate & display the drop-down takes much longer time
2) when the grid header cell is clicked once depending on the condition a control will be visible
   if i again click another header cell wthout  making the display control visible false the javascript is not getting executed
3)it works fine in FF  but in IE if i dont give alert in script the button event doesnot get fired