CheckBox server changed event : CheckBox « HTML Controls « ASP.NET Tutorial

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="ChangeEvents" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Change Events</title>
</head>
<body>
    <form id="form1" runat="server" >
    <div>
        <select runat="server" 
                id="List1" 
                size="5" multiple 
                Name="List1" 
                onserverchange="List1_ServerChange">
        <option>Option 1</option>
        <option>Option 2</option>
    </select>
    <br/>
    <input type="text" 
           runat="server" 
           ID="Textbox1" 
           Size="10"
           Name="Textbox1" 
           OnServerChange="Ctrl_ServerChange"><br/>
    <input type="checkbox" 
           runat="server" 
           ID="Checkbox1"
           Name="Checkbox1" 
           OnServerChange="Ctrl_ServerChange">Option text<br/>
        &nbsp;
    <input type="submit" 
           runat="server" 
           ID="Submit1" 
           Name="cmdSubmit"
           value="Submit Query" 
           onserverclick="Submit1_ServerClick">
       </div>
    </form>
</body>
</html>

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;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class ChangeEvents : System.Web.UI.Page
{
  protected void Page_Load(object sender, System.EventArgs e)
  {
    if (!Page.IsPostBack)
    {
      List1.Items.Add("Option 3");
      List1.Items.Add("Option 4");
      List1.Items.Add("Option 5");
    }
  }

  protected void Ctrl_ServerChange(object sender, System.EventArgs e)
  {
    Response.Write("<li>ServerChange detected for " + sender + "</li>");
  }

  protected void List1_ServerChange(object sender, EventArgs e)
  {
    Response.Write("<li>ServerChange detected for List1. " + "The selected items are:</li><br/>");
    foreach (ListItem li in List1.Items)
    {
      if (li.Selected)
        Response.Write("&nbsp;&nbsp;- " + li.Value + "<br/>");
    }

  }
  protected void Submit1_ServerClick(object sender, EventArgs e)
  {
    Response.Write("<li>ServerClick detected for Submit1.</li>");
  }
}
4.3.CheckBox
	4.3.1.	CheckBox server changed event