Hi there,
its working fine.and please compile it well.use below code for testing
and don't forgate to add AjaxControlToolkit.dll in your references.
on.aspx page:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="SendingMail.WebForm1" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajaxToolkit" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body> <asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<form id="form1" runat="server">
<ajaxToolkit:AjaxFileUpload ID="AjaxFileUpload1" ThrobberID="myThrobber"
ContextKeys="fred"
AllowedFileTypes="jpg,jpeg"
MaximumNumberOfFiles=10
runat="server"/>
</form>
</body>
</html>