Enhancing Search functionality

[pedro]

Has anyone attempted to tailor the search function to a series of drop down menus. I know how to make the drop down menus such as the "manufacturer" drop down in advanced search, but what I would like to do is have the results of the first drop down menu determine the options in the next one and so on.

 

For example, If the first drop down gave the customer ten types of products, then options listed in the second menu would only be the options that pertain to the product selected in the first menu. I've seen it done on sites using ASP, but can't find anything using PHP.

 

Thanks