var theImages = new Array()
theImages[0] = 'banniere1.jpg'
theImages[1] = 'banniere2.jpg'
theImages[2] = 'banniere3.jpg'
theImages[3] = 'banniere4.jpg'
theImages[4] = 'banniere5.jpg'
theImages[5] = 'banniere6.jpg'
theImages[6] = 'banniere7.jpg'
theImages[7] = 'banniere8.jpg'
theImages[8] = 'banniere9.jpg'
theImages[9] = 'banniere10.jpg'
theImages[10] = 'banniere11.jpg'

var j = 0
var p = theImages.length;
var preBuffer = new Array()
for (i = 0; i < p; i++){
preBuffer[i] = new Image()
preBuffer[i].src = theImages[i]
}
var whichImage = Math.round(Math.random()*(p-1));
function showImage(){
document.write('<img src="images/'+theImages[whichImage]+'">');
}