if (document.images) {
	img1on = new Image();
	img1on.src = "images/nav/about_on.gif";  
	img2on = new Image();
	img2on.src = "images/nav/how_on.gif";  
	img3on = new Image();
	img3on.src = "images/nav/showreel_on.gif";  
	img4on = new Image();
	img4on.src = "images/nav/testimonials_on.gif";  
	img5on = new Image();
	img5on.src = "images/nav/contact_on.gif";  

	img1off = new Image();
	img1off.src = "images/nav/about.gif"; 
	img2off = new Image();
	img2off.src = "images/nav/how.gif";  
	img3off = new Image();
	img3off.src = "images/nav/showreel.gif";  
	img4off = new Image();
	img4off.src = "images/nav/testimonials.gif";  
	img5off = new Image();
	img5off.src = "images/nav/contact.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");        
	}	
}