function popupOptimum(url) {
  var vars = "left=0,top=0,screenX=0,screenY=0,height=";
  vars += (screen.availHeight - 50);
  vars += ",width=";
  vars += (screen.availWidth - 10);
  vars += ",directories=0,fullscreen=0,status=1,toolbar=0,location=0,resizable=1";
  var Win = window.open(url,"popup",vars);
}