<script type="text/javascript">
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_initializeRequest(initializeRequest);
prm.add_endRequest(endRequest);
var _postBackElement;</br>
function initializeRequest(sender, e)
{
if (prm.get_isInAsyncPostBack())
{ e.set_cancel(true); }
var m = document.getElementById('divGrid');
scrollTop=m.scrollTop;
}
function endRequest(sender, e)
{
var m = document.getElementById('divGrid');
m.scrollTop = scrollTop;
}
</script>
try adding the following in web.config under <system.web>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>
<httpModules>
<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>