var alreadyRun = false;
function randomimage() {
   	if (alreadyRun) { return; }
   	alreadyRun = true;
        var p = 4;  // Set the number of images to be randomized
	var whichImage = Math.round(Math.random()*(p-1));
// $('AP-banner a'}.css('background-image', 'url(http://www.utsunion.uts.edu.au/images/css/ap_promotion' + whichImage+1 + '.png');
	document.getElementById('AP-banner').style.backgroundImage="url(http://www.utsunion.uts.edu.au/images/css/ap_promotion" + (whichImage+1) + ".png)";
}