// preload navigation images:

        if (document.images) {
               
                optiva_on = new Image();
                optiva_on.src = "images/optiva_on.gif";
                optiva_off = new Image();
                optiva_off.src = "images/optiva_off.gif";
                
                login_on = new Image();
                login_on.src = "images/login_on.gif";
               	login_off = new Image();
                login_off.src = "images/login_off.gif";    
              
}
                        
function hiLite(imgID,changeID) {
                        
        if (document.images) {
        document.images[imgID].src = eval(changeID + ".src");
        return true;
        }
}