// Function that return a number between 0 and "nums - 1" function getRandom(nums) { var ranNum= Math.round(Math.random()*nums); return ranNum; } // Tells us how many images we have available. var numberOfImages = 3; var randomNumber = getRandom(numberOfImages); // Create an array to hold the names of all images. var image = new Array(numberOfImages); image[0]="images/banner1_sidebar.jpg"; image[1]="images/banner2_sidebar.jpg"; image[2]="images/banner3_sidebar.jpg"; image[3]="images/banner4_sidebar.jpg"; // Write the img tag with a random image name. document.write("");