function popWindow ( url, width, height ) {
   var left = Math.floor ( ( screen.width - width ) / 2 );
   var top = Math.floor ( ( screen.height - height ) / 2 );
   var winParms = "top=" + top + ",left=" + left + ",height=" + height + ",width=" + width;
   winParms += "," + "titlebar=no,toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no,alwaysRaised=yes,AlwaysOnTop=yes";
   popupWindow = window.open ( url, "Tsonos", winParms );
}