Comments by Deepak Kr Choudhary (Top 3 by date)

now you have to use trigger
like following example
<div>

<br />
<asp:ScriptManager ID="ScriptManager1" runat="server">

<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<c>
<fieldset style="width:30%">
Update Panel-1
<asp:Label ID="lbl1" runat="server" ForeColor="green"/><br />
<asp:Button ID="btnUpdate1" runat="server" Text="Update Both Panels" OnClick="btnUpdate1_Click" />
<asp:Button ID="btnUpdate2" runat="server" Text="Update This Panel" OnClick="btnUpdate2_Click" />
</fieldset>


<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
<c>
<fieldset style="width:30%">
Update Panel-2
<asp:Label ID="lbl2" runat="server" ForeColor="red" />
</fieldset>

<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnUpdate1" EventName="Click" />
</Triggers>


</div>



c# Code


protected void btnUpdate1_Click(object sender, EventArgs e)
{
lbl1.Text = DateTime.Now.ToLongTimeString();
lbl2.Text = DateTime.Now.ToLongTimeString();
}
protected void btnUpdate2_Click(object sender, EventArgs e)
{
lbl1.Text = DateTime.Now.ToLongTimeString();
lbl2.Text = DateTime.Now.ToLongTimeString();
}