if (document.images)
   {
     pic1on= new Image(100,29);
     pic1on.src="../images/home-on.gif";  
     pic2on= new Image(100,29);
     pic2on.src="../images/company-on.gif"; 
     pic3on= new Image(100,29);
     pic3on.src="../images/services-on.gif";
     pic4on= new Image(100,29);
     pic4on.src="../images/clients-on.gif";
     pic5on= new Image(100,29);
     pic5on.src="../images/news-on.gif"; 
     pic6on= new Image(100,29);
     pic6on.src="../images/contact-on.gif";  

     pic1off= new Image(100,29);
     pic1off.src="../images/home.gif";
     pic2off= new Image(100,29);
     pic2off.src="../images/company.gif";
     pic3off= new Image(100,29);
     pic3off.src="../images/services.gif";
     pic4off= new Image(100,29);
     pic4off.src="../images/clients.gif";
     pic5off= new Image(100,29);
     pic5off.src="../images/news.gif";
     pic6off= new Image(100,29);
     pic6off.src="../images/contact.gif";

   }

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

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