userAgent = window.navigator.userAgent;
browserVers = parseInt(userAgent.charAt(userAgent.indexOf("/")+1),10);
function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function findElement(n,ly) {
	if (browserVers < 4)		return document[n];
	var curDoc = ly ? ly.document : document;
	var elem = curDoc[n];
	if (!elem) {
		for (var i=0;i<curDoc.layers.length;i++) {
			elem = findElement(n,curDoc.layers[i]);
			if (elem) return elem;
		}
	}
	return elem;
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		var img;
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			img = null;
			if (document.layers) {
				img = findElement(changeImages.arguments[i],0);
			}
			else {
				img = document.images[changeImages.arguments[i]];
			}
			if (img) {
				img.src = changeImages.arguments[i+1];
			}
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		but1on = newImage("../images/nav_01on.png");
		but2on = newImage("../images/nav_03on.png");		
		but3on = newImage("../images/nav_05on.png");
		but4on = newImage("../images/nav_07on.png");
		but5on = newImage("../images/nav_08on.png");
		but6on = newImage("../images/nav_11on.png");		
		but7on = newImage("../images/nav_13on.png");
		but8on = newImage("../images/nav_15on.png");		
		but1off = newImage("../images/nav_01.png");
		but2off = newImage("../images/nav_03.png");		
		but3off = newImage("../images/nav_05.png");
		but4off = newImage("../images/nav_07.png");
		but5off = newImage("../images/nav_08.png");
		but6off = newImage("../images/nav_11.png");		
		but7off = newImage("../images/nav_13.png");
		but8off = newImage("../images/nav_15.png");		
		enteron = newImage("../gfx/nav_13.png");
		enteroff = newImage("../gfx/nav_15.png");		
		butxon = newImage("../gfx/backon.png");
		butxoff = newImage("../gfx/back.png");		
		preloadFlag = true;
	}
}