private properties

Hello fellow developers!

I have a question that is burning me since some days.

I have this controller, let say called: mainmap.js that among other things, shows a map and some annotations loaded from a REST webservice. Each time you click on an annotation, some data is loaded in a view that show on top of map. Between callbacks and eventlisteners, I have this properties that area defined inside the controller file, and used in some methods.

var _curCoord = {
    lat : null,
    lon : null
};
 
var _curProp = {
    idprop : null
};

Called inside an eventlistener to store data

if(evt.clicksource == 'pin'){
        topView.animate(
        {
          bottom:10,
          duration:500
        });
        topviewopen = true;
 
        // carga la informacion de la propiedad
        _curProp.idprop = evt.annotation.titleid;
        Ti.API.info('idprop set ' + _curProp.idprop);
        loadPropData(evt.annotation.titleid);
        loadPropImages(evt.annotation.titleid);
    }

then I have to use the data stored to save stuff on the webservice or refresh data

if(_curProp.idprop == 'undefined')
    return;
 
Ti.API.info('toggle fav ' + _curProp.idprop);
if(!favico.favorite)
{
    // marcar la propiedad como favorita
    properties.toggleFavoritoUsuario(_curProp.idprop,0,{
        success: function(data) {
            var prop = data[0];
            Ti.API.info(prop);
            favico.backgroundImage = 'favorite_icosel30.png';
            favico.favorite = true;
        }
    });
}

Then thing is that some times _curProp.idprop has data, and randomly, other times just is undefined.

How would you solve this kind of situation?

Thanks for any advice :D