// Create arrays to contain all the values 
// for image locations
function random() {
image = new Array

image[1]="header/header1.gif"
image[2]="header/header2.gif"
image[3]="header/header3.gif"
image[4]="header/header4.gif"

// Create a random number between 1 and five
random_num = (Math.round((Math.random()*3)+1))

// Write the image tag with a random array element
document.write("<img src=\"" + image[random_num] + "\" width=\"280\" height=\"75\" border=\"0\" alt=\"Rationale... by David Chien\" />");
}