writing a MySQL search function

I have a 13 column MySQL table... Writing from a form to the DB is no problem... Printing the results to an HTML table, according to a query string appended URL, is also done already... So, now I can basically write links+query strings into my web pages that will return results from a database. Basic, yes...but a decent first step for someone who couldn't even conceive of it a week ago. Now, what I really need to do is modify the .php file that displays the results, so that I can pass the necessary query variables via a search form. I need to be able to search by all or one or none (or any combination) of, I guess 4-5 fields from the db... How do you write the query? I'm thinking that the query has to be dynamically generated...but can't really picture it beyond that. If you know of any code snippets, articles or tutorials that cover this sort of thing, I'd really appreciate it. I think once I get an idea of how the function works, I'll be able to actually write it... thanks, John Corry Neon Cowboy Design http://www.neoncowboy.com