Unable to convert value to float

I have this listener

mapView.addEventListener('longclick',function(e){
            Ti.API.info(e.type);
            Ti.API.info(e.latitude + "," + e.longitude);
 
            var tmpAnn = MapModule.createAnnotation({
                latitude: e.latitude,
                longitude: e.longitude,
                title:"GO?",
                pincolor:Titanium.Map.ANNOTATION_AZURE,
                animate:true,
                leftButton: 'images/plus.png',
                myid:3 // CUSTOM ATTRIBUTE THAT IS PASSED INTO EVENT OBJECTS
            });
 
            mapView.addAnnotation(tmpAnn);
 
        });

and when I long click on a map the app is blocked and gives me this error

[ERROR] :  TiApplication: (main) [67062,105495] Sending event: exception on thread: main msg:java.lang.NumberFormatException: Unable to convert value to float.; Titanium 3.2.3,2014/04/22 10:17,b958a70
[WARN] :   dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x414aa930)
[ERROR] :  TiApplication: java.lang.NumberFormatException: Unable to convert value to float.

I tried to make 'parseFloat(e.latitude)' and 'parseFloat(e.longitude)' but nothing changes