if (document.images) {
	chamber_off = new Image();
		chamber_off.src = "/assets/btn_chamber_off.gif" ;
		chamber_on = new Image();
		chamber_on.src = "/assets/btn_chamber_on.gif" ; community_off = new Image();
		community_off.src = "/assets/btn_community_off.gif" ;
		community_on = new Image();
		community_on.src = "/assets/btn_community_on.gif" ; visitors_off = new Image();
		visitors_off.src = "/assets/btn_visitors_off.gif" ;
		visitors_on = new Image();
		visitors_on.src = "/assets/btn_visitors_on.gif" ; 
}