add DataKeyNames="forumId" in gridview then access fields like
int intforumid = Convert.ToInt32(GridView1.DataKeys[row.RowIndex].Values[0]);
//GridCall.SelectedRow.FindControl("txtCallID").ToString();
add DataKeyNames="forumId" in gridview then access fields like
int intforumid = Convert.ToInt32(GridView1.DataKeys[row.RowIndex].Values[0]);
//GridCall.SelectedRow.FindControl("txtCallID").ToString();