var overImgName = "_on";
var outImgName  = "_off";

var rollOverImg   = true;
var rollOverInput = true;
var rollOverMap   = true;

var Format = function(){
	var doc      = document;
	var na       = navigator.userAgent;

	this.doc     = doc;
	this.Opera   = window.opera;
	this.IE      = (doc.all && !window.opera);
	this.macIE   = (na.toLowerCase().indexOf('mac') != -1 && na.toLowerCase().indexOf('msie') != -1);
	this.macFF   = (na.indexOf('mac') != -1 && na.indexOf('firefox')!=-1);
};

Format.prototype = {
	onload: function(func){
		if(this.Opera){
			window.addEventListener('load', func, false);
		}else if(this.macIE){
			window.onload = function(){ func(); }
		}else if(this.IE){
			window.attachEvent('onload', func);
		}else if(window.addEventListener){
			window.addEventListener('load', func, false);
		}else{
			window.onload = function(){
				func();
			}
		}
	},

	ID: function(){
		if(arguments.length > 1){
			var getAE = [];
			for(i=0; i<arguments.length; i++){
				if(this.doc.all) getAE[i] = this.doc.all(arguments[i]);
				else if(this.doc.getElementById) getAE[i] = this.doc.getElementById(arguments[i]);
			}
			return getAE;
		}else{
			if(this.doc.all) return this.doc.all(arguments[0]);
			else if(this.doc.getElementById) return this.doc.getElementById(arguments[0]);
		}
	},

	check: function(chkID){
		var flag = true;
		if(!chkID) return false;
		else{
			if(chkID.length){
				for(i=0; i<chkID.length; i++) if(!chkID[i]) return false;
			}else{
				if(!chkID) return false;
			}
		}
		return flag;
	}
};

var FK = new Format;


var FKroFormat = function(over,out){
	this.tagName = FK.doc.getElementsByTagName;
	this.regOver = new RegExp(outImgName + "+(\.[a-z]+)$");
	this.regOut  = new RegExp(overImgName + "+(\.[a-z]+)$");
};

FKroFormat.prototype = {
	init: function(){
		if(rollOverImg) FKro.roImg();
		if(rollOverInput) FKro.roInput();
	},

	roImg: function(){
		if(this.tagName){
			var imgTagData = this.getTag('img');
			var useImg = [];
			var useCount = 0;

			for(i=0; i<imgTagData.length; i++){
				var imgSrc = imgTagData[i].getAttribute("src");
				if(imgSrc.match(FKro.regOver)){
					this.preload(imgSrc,FKro.regOver,overImgName);

					if(rollOverMap){
						var imgMap = imgTagData[i].getAttribute("usemap");
						if(imgMap){
							useImg[useCount] = imgTagData[i];
							useCount++;
							continue;
						}
					}

					imgTagData[i].onmouseover = function() {
						FKro.action(this,FKro.regOver,overImgName);
					}
					imgTagData[i].onmouseout = function() {
						FKro.action(this,FKro.regOut,outImgName);
					}
				}
			}

			if(rollOverMap && (useCount > 0)){
				var mapName = [];

				for(i=0; i<useImg.length; i++){
					mapName[i] = useImg[i].getAttribute("usemap").substring(1);

					if(FK.check(FK.ID(mapName[i]))){
						FK.ID(mapName[i]).onmouseover = function(){
							for(x=0; x<useImg.length; x++){
								if(this.id == mapName[x]){
									FKro.action(useImg[x],FKro.regOver,overImgName);
									break;
								}
							}
						}

						FK.ID(mapName[i]).onmouseout = function(){
							for(x=0; x<useImg.length; x++){
								if(this.id == mapName[x]){
									FKro.action(useImg[x],FKro.regOut,outImgName);
									break;
								}
							}
						}
					}
				}
			}
		}
	},

	roInput: function(){
		if(this.tagName){
			var imgTagData = this.getTag('input');

			for(i=0; i<imgTagData.length; i++){
				var imgSrc = imgTagData[i].getAttribute("src");
				var imgType = imgTagData[i].getAttribute("type");
				if((imgType.match('image')) && (imgSrc.match(FKro.regOver))){
					this.preload(imgSrc,FKro.regOver,overImgName);

					imgTagData[i].onmouseover = function() {
						FKro.action(this,FKro.regOver,overImgName);
					}
					imgTagData[i].onmouseout = function() {
						FKro.action(this,FKro.regOut,outImgName);
					}
				}
			}
		}
	},

	getTag: function(tag){
		return FK.doc.getElementsByTagName(tag);
	},

	preload: function(src,reg,name){
		var pre = new Image();
		pre.src = src.replace(reg, name + "$1");		
	},

	action: function(target,reg,name){
		target.setAttribute("src", target.getAttribute("src").replace(reg, name + "$1"));
	}
};

var FKro = new FKroFormat;

FK.onload(FKro.init);