function popUp (URL,w,h){
	var x = (screen.width - w) / 2;
	var y = (screen.height - h) / 2;
	window.open(URL,"ventana1","width="+(w)+", height="+(h)+", scrollbars=no, menubar=no, location=no, left="+(x)+", top="+(y)+", resizable=no");
	
}