navLoaded = false;
var NAVBUTTONS = 0;

function loadnavImages() {
	var imgRef;
	var docRef = (ns4) ? document.nav.document : document;
	
	for (var i = 0; i < docRef.images.length; i++) {
		if (docRef.images["nav"+i]) NAVBUTTONS++;
	}
	navImages = new Array(NAVBUTTONS*2);	
	
	for (var i = 0; i < NAVBUTTONS; i++) {
		navImages[i] = new Image;
		navImages[i+NAVBUTTONS] = new Image;
		imgRef = docRef.images["nav" + i].src;
		navImages[i].src = imgRef;
		navImages[i+NAVBUTTONS].src = imgRef.replace(/_off/,"_on");
	}

	return true;
}

function navOn(imgID) {
	if (navLoaded == false) return;
	var docRef = (is.nav) ? document.nav.document : document;
	docRef.images["nav" + imgID].src = docRef.images["nav" + imgID].src.replace(/_off/,"_on");
	//alert("nav" + imgID);
}

function navOff(imgID) {
	if (navLoaded == false) return;

	var docRef = (is.nav) ? document.nav.document : document;
	docRef.images["nav" + imgID].src = docRef.images["nav" + imgID].src.replace(/_on/,"_off");
}