var image = new Array()

image[0] = 'images/recommendation1.gif'
image[1] = 'images/recommendation2.gif'
image[2] = 'images/recommendation3.gif'
image[3] = 'images/recommendation4.gif'
image[3] = 'images/recommendation5.gif'
image[3] = 'images/recommendation6.gif'

var j = 0
var p = image.length;
var buffer = new Array()
for (i = 0; i < p; i++){
   buffer[i] = new Image()
   buffer[i].src = image[i]
}

var thisImage = Math.round(Math.random()*(p-1));
function showImage(){
document.write('<img src="'+image[thisImage]+'">');
}