browserName=navigator.appName; 
browserVer=parseInt(navigator.appVersion);

  if ((browserName=="Netscape" && browserVer>=3) || (browserName=="Microsoft Internet Explorer" && browserVer>=4))    
  version="n3";
  else
    version="n2";

  if (version=="n3")
   {
     pic1on= new Image(138,77);
     pic1on.src="http://www.post-gazette.com/images4/20091227bestphotos2009_138_pt.jpg"

     pic1off= new Image(138,77);
     pic1off.src="http://www.post-gazette.com/images4/20091227bestphotos2009_138.jpg";  
   }


function lightup(imgName)
 {
   if (version=="n3")
    {
      imgOn=eval(imgName + "on.src");
      document[imgName].src= imgOn;
    }
 }

function turnoff(imgName)
 {
   if (version=="n3")
    {
      imgOff=eval(imgName + "off.src");
      document[imgName].src= imgOff;
    }
 }