if (document.images) {
            nav0on = new Image();  nav0on.src = "http://www.trebleseven.com/assets/email2.gif";
            nav0off = new Image();  nav0off.src = "http://www.trebleseven.com/assets/email1.gif";

            nav1on = new Image();  nav1on.src = "http://www.trebleseven.com/assets/buttons/home2.gif";
            nav1off = new Image();  nav1off.src = "http://www.trebleseven.com/assets/buttons/home1.gif";
            nav2on = new Image();  nav2on.src = "http://www.trebleseven.com/assets/buttons/news2.gif";
            nav2off = new Image();  nav2off.src = "http://www.trebleseven.com/assets/buttons/news1.gif";
            nav3on = new Image();  nav3on.src = "http://www.trebleseven.com/assets/buttons/contact2.gif";
            nav3off = new Image();  nav3off.src = "http://www.trebleseven.com/assets/buttons/contact1.gif";
            nav4on = new Image();  nav4on.src = "http://www.trebleseven.com/assets/buttons/branding2.gif";
            nav4off = new Image();  nav4off.src = "http://www.trebleseven.com/assets/buttons/branding1.gif";
            nav5on = new Image();  nav5on.src = "http://www.trebleseven.com/assets/buttons/corpreports2.gif";
            nav5off = new Image();  nav5off.src = "http://www.trebleseven.com/assets/buttons/corpreports1.gif";
            nav6on = new Image();  nav6on.src = "http://www.trebleseven.com/assets/buttons/literature2.gif";
            nav6off = new Image();  nav6off.src = "http://www.trebleseven.com/assets/buttons/literature1.gif";
            nav7on = new Image();  nav7on.src = "http://www.trebleseven.com/assets/buttons/interactive2.gif";
            nav7off = new Image();  nav7off.src = "http://www.trebleseven.com/assets/buttons/interactive1.gif";
            nav8on = new Image();  nav8on.src = "http://www.trebleseven.com/assets/buttons/exhibitions2.gif";
            nav8off = new Image();  nav8off.src = "http://www.trebleseven.com/assets/buttons/exhibitions1.gif";
            nav9on = new Image();  nav9on.src = "http://www.trebleseven.com/assets/buttons/extra2.gif";
            nav9off = new Image();  nav9off.src = "http://www.trebleseven.com/assets/buttons/extra1.gif";

            }

// Navigation rollovers

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

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