function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

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

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		_btn_about_over = newImage("/images_b/menu/_btn_about-over.gif");
		_btn_watershed_over = newImage("/images_b/menu/_btn_watershed-over.gif");
		_btn_challenges_over = newImage("/images_b/menu/_btn_challenges-over.gif");
		_btn_stewardship_over = newImage("/images_b/menu/_btn_stewardship-over.gif");
		_btn_programs_over = newImage("/images_b/menu/_btn_programs-over.gif");
		_btn_library_over = newImage("/images_b/menu/_btn_library-over.gif");
		_btn_news_over = newImage("/images_b/menu/_btn_news-over.gif");
		_btn_sitemap_over = newImage("/images_b/menu/_btn_sitemap-over.gif");
		_btn_contact_over = newImage("/images_b/menu/_btn_contact-over.gif");
		preloadFlag = true;
	}
}