codice:
function preload(clip){
	clip.stop();
    car = clip.getBytesLoaded();
	tot = clip.getBytesTotal();
	perc = Math.floor((car/tot)*100);
	clip.createTextField("testo", 1, 0, 0, 200, 20);
	clip.testo.wordWrap = true;
	format = new TextFormat();
	format.color = 0x123466;
	format.font = "Verdana";
	if(!isNaN(perc)) {
		clip.testo.text = "Caricamento.."+perc+"%";
		clip.testo.setTextFormat(format);
	}
	if (car >= tot && car > perc && perc == 100) {
		clearInterval(a);
		clip.testo.text = "";
                clip.gotoAndPlay(2);
	}
}

//per richiamarlo
loadMovie("prova.jpg", "mc1");
a = setInterval(preload, 50, mc1);
ciao