title: need help converting and calculating distance
body: <p>I'm stuck and need some help. I have a database that has over 3000 latitudes and longitudes and I'm trying to convert them to decimal lat and lon so I can display the distance between two coordinates. The two coordinates are passed in the url of the page. The first (lat1 &amp; lon1) is already converted but the second (lat2 &amp; lon2) is not. The latitude and Longitude in my database are stored like This:  26°56.34308'   -094°41.32328' so I'm thinking that the commas should probably be removed.  I've got some code from a few sources but I'm not sure how to put them together properly.</p>
  
  <pre><code>///// Get the two locations from the url
  
  $lat1 = $_GET[lat1];
  $lon1 = $_GET[lon1];
  
  ////// lat2 &amp; Lon2 are the ones that need to be converted
  
  $lat2 = $_GET[lat2];
  $lon2 = $_GET[lon2];
  
  ///// Convert lat2 &amp; lon2 into decimal format
  
  $pos1 = strrpos($mystring, "°");
  $pos2 = strrpos($mystring, ".");
  $pos3 = strrpos($mystring, "'");
  // Get subsring from a string: substr(source, start, length)
  $deg = substr($mystring, 0, $pos1);
  $min = substr($mystring, $pos1, $pos2 - $pos1);
  $sec = substr($mystring, $pos2, $pos3 - $pos2);
  
  function DMStoDEC($deg,$min,$sec) {
  // Converts DMS ( Degrees / minutes / seconds )
  // to decimal format longitude / latitude
      return $deg+((($min*60)+($sec))/3600);
  }
  
  //////calculate the distance
  
  function distance($lat1, $lon1, $lat2, $lon2, $unit) {
      $theta = $lon1 - $lon2;
      $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +
          cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
      $dist = acos($dist);
      $dist = rad2deg($dist);
      $miles = $dist * 60 * 1.1515;
      $unit = strtoupper($unit);
  
      if ($unit == "K") {
          return ($miles * 1.609344);
      } else if ($unit == "N") {
          return ($miles * 0.8684);
      } else {
          return $miles;
      }
  }
  
  // Miles
  echo distance($lat1, $lon1, $lat2, $lon2, "m") . " miles&lt;br&gt;&lt;br&gt;";
  
  //Kilometers
  echo distance($lat1, $lon1, $lat2, $lon2, "k") . " kilometers&lt;br&gt;&lt;br&gt;";
  
  //Nautical miles
  echo distance($lat1, $lon1, $lat2, $lon2, "N") . " Nautical miles";
  </code></pre>