Third party app? Not necessarily. After all, YOU'RE a third party as well!
What you need is a database of post office locations that includes lat/long
information on each post office. Each Post Office is a zip code. Then you
need a database of whatever you're trying to locate, which also includes
lat/long information about the locations (zip code not necessary). Then you
create a query that uses a bit of trigonometry to get the distance from the
zip code to each of the locations in your locations table, by calculating
the distance between the lat/long of the post office to the lat/longs of
each location. This part can be little tricky, as calculating distances
between lat/longs means calculating distances on the surface of an
ellipsoid, not a sphere, but depending on how accurate you need the results
to be, you can approximate a sphere using the Mean Earth radius.
--
HTH,
Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.
"David Lozzi" <dlozzi@(remove)delphi-ts.com> wrote in message
news:eO****************@tk2msftngp13.phx.gbl...
Hey All,
I need to add a locator service for asp.net where a user would specify a zip
code and then the returned list would be displayed in order of closest to
furthest. I realize this is a third pary app, but who/what do you
recommend??
Thanks!
--
David Lozzi
Web Applications/Network Specialist
Delphi Technology Solutions, Inc.
dlozzi@(remove)delphi-ts.com