if (navigator.userAgent.indexOf("Mozilla/4") >= 0){
		Image1 = new Image()
		Image1.src = "images/butt_return_on.gif"
		Image2 = new Image()
		Image2.src = "images/butt_next_on.gif"
		Image3 = new Image()
		Image3.src = "images/butt_prev_on.gif"
		Image4 = new Image()
		Image4.src = "images/top_port_close_on.gif"
	}
	function rollinGif(imagenum){
		document.images[ imagenum ].src= "images/" + imagenum + "_on.gif";
	
	}
				
	function rolloutGif(imagenum){
		document.images[ imagenum ].src= "images/" + imagenum + "_off.gif";
	
	}