Menu populated based on previous menu

Searched all the sites I could find for this problem to no avail. I have two dropdown menus in a form. The first menu contains a list of MANUFACTURERS obtained from a database. The second contains a list of MODELS also obtained from the database. I want the second menu to be populated based upon the selection in the first. In other words, once a visitor has selected a MANUFACTURER they'll be presented with a list of MODELS that are available from the selected MANUFACTURER. I know how to do the queries, but don't know how to initiate the query and rebuild the second menu when the first selection is made without adding a SUBMIT button and loading a second page. Anyone know how to accomplish this? Thanx in advance. -- Robb Kerr Digital IGUANA Helping Digital Artists Achieve their Dreams http://www.digitaliguana.com http://www.cancerreallysucks.org