On 1/19/07, Casey Crookston <caseyc at intellisoftmn.com> wrote: > We've all seen the tools that allow you to search for a business within > 10, 50, 100, 500 miles of a given zip code. Can anyone point me in the > direction of how this is done? We have not yet determined if the site > will be in PHP or .NET, so we are open to all suggestions. You need a database that relates zip codes or addresses to lat/long coordinates. You then take a supplied zip or address, convert it to lat/long coords using your DB, convert the destinations to lat/long if not already done, then use simple trig (can find this algorithm anywhere via google) to determine the distance between the two lat/long coords. The more precise you need it, the more precise your database has to be. -- Matt Warden Cleveland, OH, USA http://mattwarden.com This email proudly and graciously contributes to entropy.