if (document.images) {        
img1on = new Image();		
img1on.src = "images/image3.gif"; 
img2on = new Image();		
img2on.src = "images/image6.gif"; 
img3on = new Image();		
img3on.src = "images/image9.gif";
img4on = new Image();		
img4on.src = "images/image12.gif";
img5on = new Image();		
img5on.src = "images/image15.gif"; 
img6on = new Image();		
img6on.src = "images/image18.gif"; 

img1off = new Image();		  	
img1off.src = "images/image1.gif"; 
img2off = new Image();		  	
img2off.src = "images/image4.gif";
img3off = new Image();		  	
img3off.src = "images/image7.gif";
img4off = new Image();		  	
img4off.src = "images/image10.gif";
img5off = new Image();		  	
img5off.src = "images/image13.gif";
img6off = new Image();		  	
img6off.src = "images/image16.gif";

}

function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "on.src");        }}
			
function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "off.src");        }}