Getting people located new a zip code...

I need to make a browse feature on my website where the user inputs a zip code (US), and selects a distance from that zip code (2 miles, 5 miles, 10 miles) and then it gets the users from the database who apply to that criteria.

Where do i begin?? lol

Well, you're going to have to store the information in a database. Then you have to figure out how you want to store the distance information (i.e. should all users have a distance to all zip codes, or should they just have one distance to a common location, etc). Then you might have to do some calculations and then display the result.

well the users all have their location stored in the database.

I have this old script thats had zip code search, let me go take a look at it.

Use the Google maps API ;)

Google Maps API, is good.

i dont want to have to use 3rd party code though...

i think this is the code that gives the zip codes... not sure though. looks complicated

PHP Code:

---

$pi = 3.14159265358979323846;
$EARTH_RADIUS = 3963.205; # diameter/2 in miles

$dist = sprintf("%.1f", $dis);

function Distance($latitude1, $longitude1, $latitude2, $longitude2)
{
  global $pi, $EARTH_RADIUS;

  $dist = 0;
  $latitude1 = $latitude1 * $pi / 180; #turn each from radians to degrees
  $longitude1 = $longitude1 * $pi / 180;
  $latitude2 = $latitude2 * $pi / 180;
  $longitude2 = $longitude2 * $pi / 180;

  if(($latitude1 != $latitude2) || ($longitude1 != $longitude2)){
    $dist = (sin($latitude1) * sin($latitude2)) + (cos($latitude1) * cos($latitude2)) * cos($longitude2 - $longitude1);
    $dist = $EARTH_RADIUS * (-1 * atan2($dist / sqrt(1 - $dist * $dist), 1) + $pi / 2);
  }

  return sprintf("%.1f", $dist);
}

//HERE IS WHERE THE FUNCTION IS CALLED

if($first && $second)
{
    $sql="select * from zips where zip like '$first'";
    $first_res=mysql_query($sql);
    $first_set=mysql_fetch_array($first_res);

    $flat = $first_set["lat"];
    $flong = $first_set["longitude"];


    $sql="select * from zips where zip like '$second'";
    $second_res=mysql_query($sql);
    $second_set=mysql_fetch_array($second_res);

    $slat = $second_set["lat"];
    $slong = $second_set["longitude"];
}
$miles = Distance($flat, $flong, $slat, $slong); 


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it looks like it gets them from a table `zips` and i am looking at the dump file, and there are 42k zip codes...

i would get those into a database and test some out. some locations you know, to see if it actually works.