il mio codice e' :

stop();

this.onEnterFrame = function (){

var perc:Number = Number(tot-par);
var tot:Number = Number(Math.round((this.getBytesTotal ()/1024)));
var par:Number = Number(Math.round((this.getBytesLoaded ()/1024)));

tot_kb.text = tot;
par_kb.text = par;
per.text = perc;

trace (typeof (tot))
trace (typeof (par))
}

perche' mi dice che perc e' NaN ?????????????????????????????????????????????????