protected void doValidation( )
{
System.out.println( getClass( ).getName( ) + ".doValidation()" );
/* Account */
Account account = _customer.getAccount( );
checkLength( "customerId", "userId_length", account.getUserId( ), 4 );
checkLength( "password", "password_length", account.getPassword( ), 4 );
/* Email */
checkNotEmpty( "email", "email_required", _customer.getEmail( ) );
/* Credit card */