Grid RowDelete

protected void gvwtest_RowDeleting(object sender, GridViewDeleteEventArgs e)
 {
     Test_BL oTest_BL = new Test_BL();
     ImageButton ibtnDelete = gvwtest.Rows[e.RowIndex].FindControl("ibtnDelete") as ImageButton;
     int Id = Convert.ToInt32(ibtnDelete.CommandArgument);
     oTest_BL.DeleteName(Id);
     FillGrid();
     DisplayMessage("Deleted Successfully");
 }