Distance Finder

distance.js

var getDistance = function(lat1,lon1,lat2,lon2){

	    var R = 6371; // km 
	    //has a problem with the .toRad() method below.
	    var dLat = toRad(lat2-lat1);  
	    var dLon = toRad(lon2-lon1);  
	    var a = Math.sin(dLat/2) * Math.sin(dLat/2) + 
	                    Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) * 
	                    Math.sin(dLon/2) * Math.sin(dLon/2);  
	    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
	    var d = R * c; 
	    return d * 1000; //Return as meters
	}
function toRad(e) {
return e * Math.PI / 180;
}