Simple DirectI domain registration script

I need a simple script that uses DirectI API to register a domain. Every domain registration form should appear after successful domain search have all type contact (administrative, technical, billing) fields available to define and should create new account or use existing one (from a dropdown menu). That's all. It should be a simple PHP script with easy to understand code and dirty HTML that shows a form if domain search succeeds and then registers domain based on user provided information (to a new or existing account). No templates, just PHP and needed API classess.