function initRollovers() {

	if (!document.getElementById) return

	var preloadArray = new Array();
	var imagesArray = document.getElementsByTagName('img');

	for (var i = 0; i < imagesArray.length; i++) {

		var imageObj = imagesArray[i];
		if (imageObj.className == 'imgover') {

			var lo_src = imageObj.src;
			var hi_src = imageObj.src.replace('_of', '_on');

			imageObj.lo_src = lo_src;
			imageObj.hi_src = hi_src;

			preloadArray[i] = new Image();
			preloadArray[i].src = hi_src;

			imagesArray[i].onmouseover = function() {
				this.src = this.hi_src
			}

			imagesArray[i].onmouseout = function() {
				this.src = this.lo_src
			}
		}
	}
}
window.onload = initRollovers;