function GetDistance( lat1, lng1, lat2, lng2){ var radLat1 = lat1 * Math.PI / 180.0 var radLat2 = lat2 * Math.PI / 180.0 var a = (lat1 - lat2) * Math.PI / 180.0; var b = (lng1 - lng2) * Math.PI / 180.0; var s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) + Math.cos(radLat1)*Math.cos(radLat2)*Math.pow(Math.sin(b/2),2))); s = s * 6378137 ;// EARTH_RADIUS; s = Math.round(s * 10000) / 10000; return s; }