if (document.images) { 

			img01on = new Image();      
			img01on.src = "images/lk_aboutover.gif"; 
            img02on = new Image();      
			img02on.src = "images/lk_servicesover.gif"; 
			img03on = new Image();      
			img03on.src = "images/lk_clientsover.gif"; 
			img04on = new Image();      
			img04on.src = "images/lk_contactover.gif"; 
   
            img01off = new Image();      
			img01off.src = "images/lk_about.gif";          
            img02off = new Image();      
			img02off.src = "images/lk_services.gif"; 
			img03off = new Image();      
			img03off.src = "images/lk_clients.gif";  
			img04off = new Image();      
			img04off.src = "images/lk_contact.gif"; 
        }

// Images turn on.

function imgOn(imgName) {

        if (document.images) {

            document[imgName].src = eval(imgName + "on.src");

        }

}

// Images turn off.

function imgOff(imgName) {

        if (document.images) {

            document[imgName].src = eval(imgName + "off.src");

        }

}