if (document.images) {
// Active Images
    imgf_1on = new Image();                       
    imgf_1on.src = "images/nav-f/nav-on-f_02.gif";  
    imgf_2on = new Image();                       
    imgf_2on.src = "images/nav-f/nav-on-f_04.gif";  
    imgf_3on = new Image();                       
    imgf_3on.src = "images/nav-f/nav-on-f_06.gif";  
    imgf_4on = new Image();                       
    imgf_4on.src = "images/nav-f/nav-on-f_08.gif";  
    imgf_5on = new Image();                       
    imgf_5on.src = "images/nav-f/nav-on-f_10.gif";  
    imgf_6on = new Image();                       
    imgf_6on.src = "images/nav-f/nav-on-f_12.gif";  

// Inactive Images
    imgf_1off = new Image();                       
    imgf_1off.src = "images/nav-f/nav-f_02.gif";  
    imgf_2off = new Image();                       
    imgf_2off.src = "images/nav-f/nav-f_04.gif";   
    imgf_3off = new Image();                       
    imgf_3off.src = "images/nav-f/nav-f_06.gif";  
    imgf_4off = new Image();                       
    imgf_4off.src = "images/nav-f/nav-f_08.gif";   
    imgf_5off = new Image();                       
    imgf_5off.src = "images/nav-f/nav-f_10.gif";  
    imgf_6off = new Image();                       
    imgf_6off.src = "images/nav-f/nav-f_12.gif";   
}

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

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