// ------------------------------------------------------------ POP UP
function popup(url,alto,ancho,vscroll){
	topV=(screen.availHeight/2) - alto/2;
	leftV=(screen.availWidth/2) - ancho/2;
	win="fullscreen=0,directories=0,resizable=0,location=0,status=0,scrollbars="+vscroll+",toolbar=0,menubar=0,width="+ancho+",height="+alto+",screenX="+topV+",screenY="+leftV+",top="+topV+",left="+leftV
	variable=window.ven
	if (variable) window.ven.close();
	ven=window.open(url,'ven',win);
	window.ven.focus();
}