if (document.images) {

homeOn = new Image(); homeOn.src="images/btn-home-over.jpg"; 	
currentOn = new Image(); currentOn.src="images/btn-current-over.jpg"; 	
backissuesOn = new Image(); backissuesOn.src="images/btn-backissues-over.jpg"; 	
mbsitesOn = new Image(); mbsitesOn.src="images/btn-mbsites-over.jpg"; 	
productsOn = new Image(); productsOn.src="images/btn-products-over.jpg"; 		

homeOff = new Image(); homeOff.src="images/btn-home.jpg"; 	
currentOff = new Image(); currentOff.src="images/btn-current.jpg"; 	
backissuesOff = new Image(); backissuesOff.src="images/btn-backissues.jpg"; 	
mbsitesOff = new Image(); mbsitesOff.src="images/btn-mbsites.jpg"; 	
productsOff = new Image(); productsOff.src="images/btn-products.jpg"; 
}

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");
}