if (document.images) {             
            
            flettoff = new Image();      
            flettoff.src = "/images/subnav/leftnav_fleet-off.gif"; 
            
            fletton = new Image();      
            fletton.src = "/images/subnav/leftnav_fleet-on.gif";
        
            
            rentaloff = new Image();      
            rentaloff.src = "/images/subnav/leftnav_rental-rates-off.gif"; 

            rentalon = new Image();      
            rentalon.src = "/images/subnav/leftnav_rental-rates-on.gif";
        
            
            surplusoff = new Image();      
            surplusoff.src = "/images/subnav/navleft_for-sale-off.gif"; 

            surpluson = new Image();      
            surpluson.src = "/images/subnav/navleft_for-sale-on.gif";            
		}

// Function to 'activate' /images.
function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "on.src");
        }
}

// Function to 'deactivate' /images.
function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "off.src");
        }
}