var eventStudents = new Array()

eventStudents[0] = 'images/4.jpg'
eventStudents[1] = 'images/5.jpg'
eventStudents[2] = 'images/6.jpg'

var j = 0
var p = eventStudents.length;
var preeBuffer = new Array()
for (i = 0; i < p; i++){
   preeBuffer[i] = new Image()
   preeBuffer[i].src = eventStudents[i]
}
var whichhImage = Math.round(Math.random()*(p-1));
function rotateStudent(){
document.write('<img border="0" src="'+eventStudents[whichhImage]+'">');
}