// background.js
var randnum = Math.random();
var inum = 8;
var rand1 = Math.round(randnum * (inum-1)) + 1;
images = new Array
images[1] = "images/1.jpg"
images[2] = "images/2.jpg"
images[3] = "images/3.jpg"
images[4] = "images/4.jpg"
images[5] = "images/5.jpg"
images[6] = "images/6.jpg"
images[7] = "images/7.jpg"
images[8] = "images/8.jpg"

var image = images[rand1]