RegisterAsyncPostBackControl method on the script manager class
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="Default"%>
Register Async Controls
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
ScriptManager1.RegisterAsyncPostBackControl(Button1);
}
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text = "Last update at: " + DateTime.Now.ToLongTimeString();
Label2.Text = "Last update at: " + DateTime.Now.ToLongTimeString();
}
}