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) {
		the_book_over = newImage("images/nav_bar/the_book-over.gif");
		excerpts_over = newImage("images/nav_bar/excerpts-over.gif");
		the_author_over = newImage("images/nav_bar/the_author-over.gif");
		resources_over = newImage("images/nav_bar/resources-over.gif");
		praise_over = newImage("images/nav_bar/praise-over.gif");
		checklists_over = newImage("images/nav_bar/checklists-over.gif");
		media_room_over = newImage("images/nav_bar/media_room-over.gif");
		buy_the_book_over = newImage("images/nav_bar/buy_the_book-over.gif");
		preloadFlag = true;
	}
}