function loadImage(){
    navImages = new Array('about','products','sitemap','contact');
    for (x=0; x<navImages.length; x++){
      img = new Image();
      img.src = 'images/' + navImages[x] + '_185_over.jpg';
    }
  } 



  function swapOver(imageName){
    document[imageName].src = 'images/' + imageName + '_185_over.jpg';
  }

  function swapOut(imageName){
    document[imageName].src = 'images/' + imageName + '_185.jpg';
  }