searching list using certain criteria from boxes

I have a list of entries which i have some search criteria in boxes that the user can select from. Depending on how many of the criteria is selected I want to pull off every entry in the list that matches these criteria.

I have managed to get this working for all criteria selected, but if the user only choose 2 or 3 out of the 7 search criteria then I am struggling to think of how to do this other than do about 1000 if statements for every combination.

Please help?

Thanks

Andy