Error: Unhandled Exception Exception: UnexpectedTypeException: Expected String, given Float

help would be much appreciated on this, i’m struggling to figure out how to fix this.

var lat = Application.Properties.getValue("latitude");

var lon = Application.Properties.getValue("longitude");

 

function onUpdate(dc) {
    lat.toString;

    lon.toString;

    var locString = lat, lon;

    // Error: Unhandled Exception Exception: UnexpectedTypeException: Expected String, given Float
    var myLocation = Position.parse(locString, Position.GEO_DEG); 
    var l = myLocation;

    if (l!=null)
    {
        l = l.toDegrees();

        find(l[0], l[1]);

        l = null;