There are few things that you can look after.
At first run the stored Procedure with the expected userID in SQL query editor and see if you are getting the desired output or not.
Put Your Connection String in Web Config file and then put a debugger at your function which is returning the datatable and another at the gridview binding the datasource.
and write your gridview binding into
if(!ispostback)
{
GridView1.DataSource = dwww.getdocall1(Convert.ToInt32(Session["UserID"]));
GridView1.DataBind();
}
on your page load
and (I think just try) It should be---
GridView1.DataSource = dtResult
Hope this helps