function abrir(mypage, myname, w, h, scroll)
{
	var winl = (screen.width - w) / 2;
	var wint = (screen.height - h) / 2;
	winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars='+scroll+',noresize';
	win = window.open(mypage, myname, winprops);
}