protected void GridView2_RowCommand(object sender, GridViewCommandEventArgs e)
 {
     if (e.CommandArgument != null)
     {
         if (e.CommandName.ToLower() == "cmddelete")
         {
             int      p    = Convert.ToInt32(e.CommandArgument);
             TrainBLL tbll = new TrainBLL();
             tbll.deletebook(p);
             Label4.Text = "Deleted successfully of id " + p;
         }
     }
 }