if (document.images) {

  imageabouton = new Image();
  imageabouton.src = "/pics/n3_about_on.gif";
  imagebookon = new Image();
  imagebookon.src = "/pics/n3_book_on.gif";
  imagespeakingon = new Image();
  imagespeakingon.src = "/pics/n3_speaking_on.gif";
  imagetestimonialson = new Image();
  imagetestimonialson.src = "/pics/n3_testimonials_on.gif";
  imagecontacton = new Image();
  imagecontacton.src = "/pics/n3_contact_on.gif";
  imageresourceson = new Image();
  imageresourceson.src = "/pics/n3_resources_on.gif";
 
  imageaboutoff = new Image();
  imageaboutoff.src = "/pics/n3_about_off.gif";
  imagebookoff = new Image();
  imagebookoff.src = "/pics/n3_book_off.gif";
  imagespeakingoff = new Image();
  imagespeakingoff.src = "/pics/n3_speaking_off.gif";
  imagetestimonialsoff = new Image();
  imagetestimonialsoff.src = "/pics/n3_testimonials_off.gif";
  imagecontactoff = new Image();
  imagecontactoff.src = "/pics/n3_contact_off.gif";
  imageresourcesoff = new Image();
  imageresourcesoff.src = "/pics/n3_resources_off.gif";
  
}

function turnOn(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "on.src");
  }
}

function turnOff(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "off.src");
  }
}