I currently have the signup form on one of my html pages so that the user can fill it out directly from the html page, click continue and go to the payment processing. But if the user enters some data that will produce an error (such as invalid characters) the form will take him to the amember signup.php page with the error messages displayed on it. How can I make these errors display on my html page instead? I know there is the file error.inc, what can I do with that?