window.onload = function() {
	if (document.getElementById('course_image') && document.getElementById('course_images')) {
		var anchors = document.getElementById('course_images').getElementsByTagName('a');
		for (var i = 0; i < anchors.length; i++) {
			anchors[i].onclick = function() {
				document.getElementById('course_image').src = this.href;
				return false;
			}
		}
	}
}