DOM = (document.getElementById) ? true : false;
NS4 = (document.layers) ? true : false;
IE = (document.all) ? true : false;
IE4 = IE && !DOM;
NS = (navigator.appName=="Netscape") ? true : false;
NS6 = NS && DOM;
MAC = (navigator.appVersion.indexOf("Mac") != -1);
 
function preload(imgObj,imgSrc) {
	if (document.images) {
		eval(imgObj + 'On = new Image()')
		eval(imgObj + 'On.src = imgSrc + "_o.gif"')
		eval(imgObj + 'Off = new Image()')
		eval(imgObj + 'Off.src = imgSrc + ".gif"')
	}
}

function img_act(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + "On.src");
	}
}

function img_inact(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + "Off.src");
	}
}

function butt_act(imgName, obj) {
	obj.src = eval(imgName + "On.src");
}

function butt_inact(imgName, obj) {
	obj.src = eval(imgName + "Off.src");
}

function changeImages() {
	if (document.images) {
    	for (var i=0; i<changeImages.arguments.length; i+=2) {
      		document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    		}
		}
}
function changeImg(img,caption) {
   document.getElementById("galleryimage").src = img;
   document.getElementById('info').innerHTML = caption;
}

function openWindow(windowURL,windowName,windowWidth,windowHeight,scroll,center) {
	newWindow = window.open(windowURL,windowName,'width='+windowWidth+',height='+windowHeight+',toolbar=0,location=0,directories=0,status=0,menuBar=0,scrollbars='+scroll+',resizable=0');
	newWindow.focus(); 
   if (center) {
      newWindow.moveTo((screen.width-windowWidth)/2,(screen.height-windowHeight)/2)
   }
}

function changeStyle(id,styleSelector,value){
	eval("document.getElementById(id).style."+styleSelector+"='"+value+"';");
}

function showElement(id) {
	document.getElementById(id).style.display = "block";
}

function hideElement(id) {
   document.getElementById(id).style.display = "none";
}

function changeCss(id,theClass) {
	document.getElementById(id).className = theClass;
}

function navChange(obj) {
   location.href = obj.value;
}