var theImages = new Array() 


theImages[0] = 'img1'
theImages[1] = 'img2'
theImages[2] = 'img3'
theImages[3] = 'img4'
theImages[4] = 'img5'


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));