protected void Page_Unload(object sender, EventArgs e)
 {
     if (menuEditingBLL != null)
     {
         menuEditingBLL.Dispose();
         menuEditingBLL = null;
     }
 }
        protected void btnEdit_Click(object sender, EventArgs e)
        {
            Menu.Name = txtName.Text;
            var cost = 0.0;

            try
            {
                cost = Double.Parse(txtCost.Text);
            }
            catch { }
            Menu.Cost    = cost;
            Menu.Details = txtDetails.Text;
            MenuEditingBLL.MenuSaveOrUpdate(Menu);
            ShowSuccess("Cập nhật menu thành công");
        }