if (document.images) {
  image1on = new Image();
  image1on.src = "http://www.jetex.co.uk/website/images/navbox1on.gif";

  image2on = new Image();
  image2on.src = "http://www.jetex.co.uk/website/images/navbox2on.gif";

  image3on = new Image();
  image3on.src = "http://www.jetex.co.uk/website/images/navbox3on.gif";
  
  image4on = new Image();
  image4on.src = "http://www.jetex.co.uk/website/images/navbox4on.gif";

  image5on = new Image();
  image5on.src = "http://www.jetex.co.uk/website/images/navbox5on.gif";

  image7on = new Image();
  image7on.src = "http://www.jetex.co.uk/website/images/navbox7on.gif";
  
  image8on = new Image();
  image8on.src = "http://www.jetex.co.uk/website/images/navbox8on.gif";

  image9on = new Image();
  image9on.src = "http://www.jetex.co.uk/website/images/navbox9on.gif";

  image1off = new Image();
  image1off.src = "http://www.jetex.co.uk/website/images/navbox1off.gif";

  image2off = new Image();
  image2off.src = "http://www.jetex.co.uk/website/images/navbox2off.gif";

  image3off = new Image();
  image3off.src = "http://www.jetex.co.uk/website/images/navbox3off.gif";

  image4off = new Image();
  image4off.src = "http://www.jetex.co.uk/website/images/navbox4off.gif";

  image5off = new Image();
  image5off.src = "http://www.jetex.co.uk/website/images/navbox5off.gif";

  image7off = new Image();
  image7off.src = "http://www.jetex.co.uk/website/images/navbox7off.gif";
  
  image8off = new Image();
  image8off.src = "http://www.jetex.co.uk/website/images/navbox8off.gif";
  
  image9off = new Image();
  image9off.src = "http://www.jetex.co.uk/website/images/navbox9off.gif";

}

function changeImages() {
 if (document.images) {
  for (var i=0; i<changeImages.arguments.length; i+=2) {
   document[changeImages.arguments[i]].src = 
     eval(changeImages.arguments[i+1] + ".src");
    }
  }
}