PHP, JavaScript and populating DropDowns

Hello, I am using mySQL and PHP to pull some data into my page. I have 2 dropdown boxes. As an example lets say dropbox1 has a list of cars and dropbox2 has a list of colours. Here's the thing. The colours for each car vary so I won't know what colours to populate the 2nd dropbox with until a car is chosen. I really want this all contained on 1 page. Is there a standard way of dealing with this? The only thing I can think of is to reload the page once the make of car is selected which would give me the opportunity to populate the 2nd drop box at that time but that doesn't seem like a good solution. I don't know much in the way of JS but is there a way to do what I need that way? Thanks. Tim Winters Manager, Creative Development Sampling Technologies Incorporated (STI) webmaster@samplingtechnologies.com csnm@samplingtechnologies.com W: 902 450 5500 C: 902 430 8498