function preloadImages(){
	if (document.images){
	
		menu_bull = newImage("images/bullet.gif");
		sl_home = newImage("images/l_home_a.gif");
		sl_cont = newImage("images/l_contacts_a.gif");
		sl_map = newImage("images/l_sitemap.gif");
		preloadFlag = true;
	}
}

addEvent("onload", preloadImages);