function image() { };  
   image = new image(); 
   number = 0;
   image[number++] = "<img src='img/banner-1.png' border='0'>" 
   image[number++] = "<img src='img/banner-2.png' border='0'>" 
   image[number++] = "<img src='img/banner-3.png' border='0'>" 
   increment = Math.floor(Math.random() * number);  document.write(image[increment]);