DB Search Engine with Zipcode Radious Filter

[mikesdesign]

[img src=\"style_emoticons/[#EMO_DIR#]/unsure.gif\" style=\"vertical-align:middle\" emoid=\":unsure:\" border=\"0\" alt=\"unsure.gif\" /] I'm trying to build a database search engine on my site and I want people to be able to select 5 miles or 10 miles from their zip code and have the search engine filter the query results to the mile radius from the zip code... Does anyone know what it takes to build this or if there is something open source that is pre-built that I can use... The professors at my school have no idea how to do this. I’ve seen this done on so many sites like Myspace Please advice...Trying to do this for my Final [img src=\"style_emoticons/[#EMO_DIR#]/unsure.gif\" style=\"vertical-align:middle\" emoid=\":unsure:\" border=\"0\" alt=\"unsure.gif\" /]

[Barand]

Basically there are 3 requirements

1 ) a db table containing zip, latitude, longitude

2 ) the places you search for need lat and long columns

3 ) an algorithm for calculating new lat (or long) = lat (or long) + x miles (Google)

For speed when searching I wouldn't worry to much about a circular search area and just search within a square +or- x miles in size.

[code]
Get lat, long for zip

minLat = lat - x miles
maxLat = lat + x miles
minLong = long - x miles
maxLong = long + x miles

SELECT places from tablename
WHERE lat BETWEEN minLat AND maxLat
AND long BETWEEN minLon AND maxLong[/code]