// JavaScript Document
function abrePop(URL,nombre,ancho,alto) {
	var w = screen.width;
	var h = screen.height;

if (document.all || document.layers) {
   w = screen.availWidth;
   h = screen.availHeight;
}

var popW = ancho; 
var popH = alto;

var leftPos = (w-popW)/2, topPos = (h-popH)/2;
  ventflot= window.open(URL, nombre,'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,copyhistory=no,width='+popW+',height='+popH+',top=' + topPos + ',left=' + leftPos);
  ventflot.focus();
//  document.location.href="background.htm"
}

function abreBegira(URL)
{
	window.opener.location=URL;
	window.opener.focus();
}