function uploadError() {
	$('progreso').innerHTML = '<p><img src="img/error.gif" width="16" height="16" alt="ERROR" /> Hubo un error, intentelo nuevamente.</p>';
}
function uploadProgress(file, bytesLoaded) {
	var progress = $('barrita');
	var percent = Math.ceil((bytesLoaded / file.size) * 295);
	progress.style.background = "#fff url(img/progressbar.png) no-repeat -" + (295 - percent) + "px 0";
	ksubidos = Math.round((bytesLoaded/1000)*100)/100;
	ktotales = Math.round((file.size/1000)*100)/100;
	kporcentaje = Math.round((ksubidos*100)/ktotales);

	$('progreso').innerHTML = '<p>'+kporcentaje+'% ('+ksubidos+' KB de '+ktotales+' KB)</p>';
}