Film database

Hi, I am wanting to set up a small database, initially with a list of the video cassettes and dvds that I own. I want to have three tables - one with the video details (video id, film id, and format - dvd or vhs), one with film details (film id, film title, director), and one with the cast details (film id, cast). I can set these tables up okay, but how do I go about writing a form in PHP to allow me to add to the database? I want to write one form that allows me to add information to all three tables at one time. Is this possible? Any help would be much appreciated.