sys.webforms.pagerequestmanager is null or not an object

Hi All,

 I am running an asp.net website and using AJAX extension. In my local macinde everything working fine, But when I upload it in server I am getting an error sys.webforms.pagerequestmanager is null or not an object. the server also run on .net3.5 framework I have got listboxes in my page, and when i try to slelect an item it's throwing this exception. My page request Manager code is

<asp:ScriptManager EnablePartialRendering="true"

ID="ScriptManager1" LoadScriptsBeforeUI="true" runat="server"></asp:ScriptManager>

<div>

<script type="text/javascript" language="javascript">

var prm = Sys.WebForms.PageRequestManager.getInstance();

prm.add_initializeRequest(initializeRequest);

prm.add_pageLoaded(pageLoaded);

prm.add_endRequest(endRequest);

var postbackElement;

// checks the PageRequestManager if there is already a postback being processed

// and aborts the postback (question: which postback does it abort?)

function pageLoaded(sender, args) {

var updatedPanels = args.get_panelsUpdated();

if (typeof(postbackElement) == "undefined") {return;

}

}

function initializeRequest(sender, args) {

document.body.style.cursor = "wait";

if (prm.get_isInAsyncPostBack())

{

//debugger

args.set_cancel(true);

}

}

function endRequest(sender, args) {document.body.style.cursor = "default";

}

</script>

 

<asp:UpdatePanel ID="UpdatePanel1" runat="server">

 

 

<ContentTemplate>

 

then the listboxes

</ContentTemplate>

</asp:UpdatePanel>

 

any help is appreciated

Source Click Here.