void CustomerEditorForm_UpdateAsync(object sender, DataActionEventArgs e)
{
CustomerAdapter ca = CreateAdapter <CustomerAdapter>();
if (!ca.ExistsWithCode(GetEditorData <Customer>()))
{
ca.Update(GetEditorData <Customer>());
}
else
{
e.Cancelled = true;
e.UserMessage = "An other customer with the specified code already exists.";
}
}