protected void btnEnviar_Click(object sender, EventArgs e)
        {
            CustomersComponent custc = new CustomersComponent();
            Customers          cust  = null;

            if (Id > 0)
            {
                cust      = custc.getCustomer(Id);
                cust.Name = txtName.Text;

                Category category = custc.GetCategory(
                    int.Parse(ddlCategories.SelectedValue));
                cust.Category = category;
                custc.UpdateCustomer(cust);
            }
            else
            {
                // agregar
                cust      = new Customers();
                cust.Name = txtName.Text;

                Category category = custc.GetCategory(
                    int.Parse(ddlCategories.SelectedValue));
                cust.Category = category;
                custc.CreateCustomer(cust);
            }
            Response.Redirect("Default.aspx");
        }
        private void LoadCustomer()
        {
            CustomersComponent custc = new CustomersComponent();
            Customers          cust  = custc.getCustomer(Id);

            txtName.Text = cust.Name;
            ddlCategories.SelectedValue = cust.Category.Id.ToString();
        }