1. Download the Toolkit at
http://ajaxcontroltoolkit.codeplex.com/
3. Extract the download
4. Add reference to AjaxControlToolKit.DLL
5. Register the DLL on your aspx page
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %> <!DOCTYPE html>
6. Add ToolkitScriptManager
<form id="form1" runat="server"> <div> <asp:ToolkitScriptManager ID="ToolKitManager1" runat="server"></asp:ToolkitScriptManager>