PHP Form Handling (2 tags)
If your PHP program is a dynamic web page (and it probably is) and your PHP program is dealing with user input (and it probably is), then you need to work with HTML forms. David Sklar, author of Learning PHP 5, offers tips for simplifying, securing, and organizing your form-handling PHP code.
Sarissa to the Rescue (2 tags)
Want to build very dynamic web interfaces like Google? Then you'll need to manage cross-browser XML compatability issues. And you'll need Sarissa.