protected void btnDelete_Click(object sender, EventArgs e)
 {
     if (!String.IsNullOrEmpty(hfId.Value))
     {
         try
         {
         CustomerFacade facade = new CustomerFacade();
         int id = Convert.ToInt32(hfId.Value);
         facade.Delete(id);
         gvCustomers.DataBind();
         lblErrorMessage.Text = Helper.DeleteRecordMessage(true);
         }
         catch (Exception exception)
         {
             lblErrorMessage.Text = Helper.DeleteRecordMessage(false);
         }
     }
 }