var preloadImgs = new Object();
function setRollOver(){
	if(document.getElementsByTagName){
		var topBtns = document.getElementsByTagName('img');
		for(var i=0;i<topBtns.length;i++){
			if(topBtns[i].getAttribute('src').match('_btn_off.gif')){
				preloadImgs[topBtns[i]] = new Image();
				preloadImgs[topBtns[i]].src = topBtns[i].getAttribute('src').replace('_btn_off.gif', '_btn_on.gif');
				topBtns[i].onmouseover = function(){
					this.setAttribute('src', this.getAttribute('src').replace('_btn_off.gif', '_btn_on.gif'));
				}
				topBtns[i].onmouseout = function(){
					this.setAttribute('src', this.getAttribute('src').replace('_btn_on.gif', '_btn_off.gif'));
				}

			}
		}
	}
}
if(window.addEventListener) window.addEventListener('load', setRollOver, false);
else if(window.attachEvent) window.attachEvent('onload', setRollOver);