// JavaScript Document
var iValue1, rNumber1;

var top_img1 = new Image();
var top_img2 = new Image();
var top_img3 = new Image();
var top_img4 = new Image();
var top_img5 = new Image();
var top_img6 = new Image();

top_img1.src = "images/image1.jpg";
top_img2.src = "images/image2.jpg";
top_img3.src = "images/image3.jpg";
top_img4.src = "images/image4.jpg";
top_img5.src = "images/image5.jpg";
top_img6.src = "images/image6.jpg";

function displayImage() {
  iValue1 = Math.random()*6;
  rNumber1 = Math.ceil(iValue1);
  if(rNumber1 == 0) rNumber1++;
  document.image1.src = eval("top_img"+ rNumber1 + ".src");
}