wildkarde

Hi, I am looking for a script that will allow me to search my web database for the closest "retailer"

You've seen these on manufacturer sites where you enter in your zip code and tell it how many miles you are willing to drive and it gives you a list of whoever in return that meet that criteria.

The problem is I have no idea what this type of script is called or if anyone has something available for purchase and so on. Can anyone out there give me a hand with this please?
Thanks!