/* rollover function
============================================================*/

var setRollOver = {

	main: function(){
		if(!document.getElementsByTagName) return false;
		var ovrImgList = document.images;
		var ovrIptList = document.getElementsByTagName('input');
		for(var i=0, len=ovrImgList.length; i<len; i++){
			if(ovrImgList[i].src.match("_off")) {
				setRollOver.preload(ovrImgList[i].src.replace(/_off./i,"_on."));
				ovrImgList[i].onmouseover = function(){
					this.src = this.src.replace(/_off./i,"_on.");
					return false;
				}
				ovrImgList[i].onmouseout = function(){
					this.src = this.src.replace(/_on./i,"_off.");
					return false;
				}
			}
		}
		for(var i=0, len=ovrIptList.length; i<len; i++){
			if(ovrIptList[i].src.match("_off")) {
				setRollOver.preload(ovrIptList[i].src.replace(/_off./i,"_on."));
				ovrIptList[i].onmouseover = function(){
					this.src = this.src.replace(/_off./i,"_on.");
					return false;
				}
				ovrIptList[i].onmouseout = function(){
					this.src = this.src.replace(/_on./i,"_off.");
					return false;
				}
			}
		}
	},

	preload: function(url){
		var preloadedImages = [];
		var len = preloadedImages.length;
		preloadedImages[len] = new Image();
		preloadedImages[len].src = url;
	},

	addEvent: function(){
		try{
			window.addEventListener("load",this.main,false);
		}catch(e){
			window.attachEvent("onload",this.main);
		}
	}

}
setRollOver.addEvent();