function image() { }; 
   image = new image();
   number = 0; 
   // imageArray
   image[number++] = "<img src='../img/banners/about_01.jpg' border='0'>"
   image[number++] = "<img src='../img/banners/about_02.jpg' border='0'>"
   image[number++] = "<img src='../img/banners/about_03.jpg' border='0'>"
   

   increment = Math.floor(Math.random() * number);  document.write(image[increment]);