function image() { }; 
   image = new image();
   number = 0; 
   // imageArray
image[number++] = "<img src='http://www.meetandeatguides.com/header/d1.jpg' border='0'>"
image[number++] = "<img src='http://www.meetandeatguides.com/header/d2.jpg' border='0'>"
image[number++] = "<img src='http://www.meetandeatguides.com/header/d3.jpg' border='0'>"
image[number++] = "<img src='http://www.meetandeatguides.com/header/d4.jpg' border='0'>"

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