if (document.images) {            // Active Images
            img1on = new Image();      
            img1on.src = "images/a-home-on.gif"; 
            img2on = new Image();      
            img2on.src = "images/a-research-on.gif"; 
            img3on = new Image();      
            img3on.src = "images/a-training-on.gif"; 
            img4on = new Image();      
            img4on.src = "images/a-cooperation-on.gif"; 
            img5on = new Image();      
            img5on.src = "images/a-consultation-on.gif"; 
            img6on = new Image();      
            img6on.src = "images/a-links-on.gif"; 
            img7on = new Image();      
            img7on.src = "images/a-contact-on.gif"; 

            img1off = new Image();      
            img1off.src = "images/a-home.gif"; 
            img2off = new Image();      
            img2off.src = "images/a-research.gif"; 
            img3off = new Image();      
            img3off.src = "images/a-training.gif"; 
            img4off = new Image();      
            img4off.src = "images/a-cooperation.gif"; 
            img5off = new Image();      
            img5off.src = "images/a-consultation.gif"; 
            img6off = new Image();      
            img6off.src = "images/a-links.gif"; 
            img7off = new Image();      
            img7off.src = "images/a-contact.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");
        }
}