function jsnav() {
	  return ((navigator.appName == "Netscape" && navigator.appVersion >= "3") ||
          (navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion >= "4"));
	}

	if ( jsnav() )

	 {
		homeOFF		= new Image(120, 50) ;
		homeOFF.src	= "bhom_0.gif" ;
		homeON		= new Image(120, 50) ;
		homeON.src	= "bhom_1.gif" ;

		vinhosOFF	= new Image(120, 50) ;
		vinhosOFF.src	= "bvin_0.gif" ;
		vinhosON	= new Image(120, 50) ;
		vinhosON.src	= "bvin_1.gif" ;

		astrosOFF	= new Image(120, 50) ;
		astrosOFF.src	= "bast_0.gif" ;
		astrosON	= new Image(120, 50) ;
		astrosON.src	= "bast_1.gif" ;

		fotosOFF	= new Image(120, 50) ;
		fotosOFF.src	= "bfot_0.gif" ;
		fotosON		= new Image(120, 50) ;
		fotosON.src	= "bfot_1.gif" ;

		poisOFF	= new Image(120, 50) ;
		poisOFF.src	= "bpoi_0.gif" ;
		poisON		= new Image(120, 50) ;
		poisON.src	= "bpoi_1.gif" ;

	  }

	function off(pic) {
		if ( jsnav() ) {
			document[pic].src=eval(pic + "OFF.src") ; }
	}
	
	
	function on(pic) {
		if ( jsnav() ) {
			document[pic].src=eval(pic + "ON.src") ; }
		}