function GuidesPopUp(t)
{
  
  var width = window.top.screen.width * .75;
  var height = window.top.screen.height * .6;
  
  if ( t.value != '' )
    window.open(t,'bg','toolbar=no,location=no,directories=no,status=no,scrollbars=yes,resizable=yes,copyhistory=no,width='+width+',height='+height);  
  else
    t.selectedIndex = 0    
}