function _openPopup(url,w,h,titel)
{
  var winProperties = "scrollbars=yes,toolbar=no,location=no,directories=no,copyhistory=no,width="+w+",height="+h+",resizable=yes";
  var popupWindow = open(url,titel,winProperties);
}

function displayPopup(url)
{
  _openPopup(url,700,500,"Popup");
}