How to use ResizableControlExtender in asp.net ajax

ResizableControlExtender
UsingResizableControlExtender.aspx

<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System.Drawing" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>

<!DOCTYPE html>
<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            Image1.ImageUrl = "~/Images/RedForest.jpg";
            Panel1.BorderColor = Color.DeepPink;
            Panel1.BorderWidth = 2;
            Panel1.HorizontalAlign = HorizontalAlign.Center;
            Panel1.BackColor = Color.Salmon;
            Panel1.Width = 450;
            Panel1.Height = 325;
        }
    }    
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Ajax ResizableControlExtender - How to use ResizableControlExtender in asp.net ajax</title>
    <style type="text/css">
        .HandleCSS
        {
            width:20px;
            height:20px;
            background-color:Red;
            }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h2 style="color:DodgerBlue; font-style:italic;">Ajax Control Toolkit Example: Using ResizableControlExtender</h2>
        <hr width="600" align="left" color="CornFlowerBlue" />
        <br /><br />
        <asp:ScriptManager 
            ID="ScriptManager1"
            runat="server"
            >
        </asp:ScriptManager>
        <cc1:ResizableControlExtender 
            ID="ReasizableControlExtender1"
            runat="server"
            TargetControlID="Panel1"
            HandleCssClass="HandleCSS"
            >
        </cc1:ResizableControlExtender>
        <asp:Panel 
            ID="Panel1"
            runat="server"
            >
            <br />
            <asp:Image 
                ID="Image1" 
                runat="server"
                />
        </asp:Panel>
    </div>
    </form>
</body>
</html>
Related asp.net ajax examples