Implementing Load GridView on ScrollDown in a UserControl

I am trying to implement this article .. Click Me in a UserControl. I downloaded the sample attached there and its working fine but i am trying to create UserControl out of it. No rows are getting loaded on scrolling down. I modified the code to look like this..
Its giving me error: The name 'Test1' does not exist in the current context.
Test1 is the Id of my USerControl. Test1 is the ID of UserControl.

var lastProductId = $("#<%=Test1.GridView1.ClientID %> tr:last").children("td:first").html();
            //get last table row in order to append the new products
            var lastRow = $("#<%=Test1.GridView1.ClientID %> tr:last");
AND,

function GetRowsCount() {//Count no. of rows except header row in the grid. var rowCount = $('#<%=Test1.GridView1.ClientID %> tr').length - 1;return rowCount;