var dom1=(document.getElementById)?1:0;
var ie4plus=(document.all)?1:0;
var ns4=(document.layers)?1:0;
var safari=(navigator.appVersion.indexOf("Safari") != -1)?1:0;
var mac=(navigator.appVersion.indexOf("Macintosh") != -1)?1:0;
var lowerUserAgent=navigator.userAgent.toLowerCase();
var opera = (lowerUserAgent.indexOf('opera')!=-1)?true:false;	

function act(imgN){
	if(document.images)document[imgN].src=eval(imgN+'over.src');
}
function inact(imgN){
	if(document.images)document[imgN].src=eval(imgN+'off.src');
}

function getElementRef(id){
	if (dom1) return document.getElementById(id);
	else if (ie4plus) return document.all[id];
	else if (ns4) return document.layers[id];
	else return null;
}

function generalOpenWin(url,winName,winFeatures){
	var winName=window.open(url,winName,winFeatures)
	if(window.focus)winName.focus();
}

function createImgObj(id) {
	return eval('document.images["' + id + '"]');
}

				
function DisplayGroup(){
	this.currentlyVis="";
	//methods
	this.switchItem=switchItem;
}

function switchItem(id){
	if(id!=this.currentlyVis){
		item2Show=getElementRef(id);
		if(item2Show)if(item2Show.style){
			item2Show.style.display='block';
		}
		item2Hide=getElementRef(this.currentlyVis);
		if(item2Hide)if(item2Hide.style) {
			item2Hide.style.display='none';
		}
		this.currentlyVis=id;
	} 
}