I have been trying to implement the ModalPopupExtender using VWD with .NET version 3.5, and I get a javascript error "'Sys' is undefined". My page is a very simple test page, so I will include it in its entirety:
<%@ Page Language="VB" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<%@ Register Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
Namespace="System.Web.UI" TagPrefix="asp" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<div>
<asp:Panel ID="Panel1" runat="server" style="display:none;">
<h1>This is a popup</h1>
<asp:Button ID="btnOK" runat="server" Text="OK" />
<asp:Button ID="btnCancel" runat="server" Text="Cancel" />
</asp:Panel>
<input type="button" id="btnShowPopup" value="Show Popup" runat="server"/>
</div>
<cc1:ModalPopupExtender ID="ModalPopupExtender1" runat="server" PopupControlID="Panel1"
TargetControlID="btnShowPopup" CancelControlID="btnCancel" BehaviorID="ModalPopupExtender1" OkControlID="btnOK">
</cc1:ModalPopupExtender>
</form>
</body>
</html>
I found a posting somewhere that suggested adding some code to the <HTTPHandlers> section of Web.Config, but this had no effect.
Any ideas how I can fix this?
Thanx.
Sheldon