img1on = new Image();           // Active images
img1on.src = "pics/ttl1_on.png";
img2on = new Image();
img2on.src = "pics/ttl2_on.png";
img3on = new Image();
img3on.src = "pics/ttl3_on.png";
img4on = new Image();
img4on.src = "pics/ttl4_on.png";
img5on = new Image();
img5on.src = "pics/ttl5_on.png";


img1off = new Image();          // Inactive images
img1off.src = "pics/ttl1_off.png";
img2off = new Image();
img2off.src = "pics/ttl2_off.png";
img3off = new Image();
img3off.src = "pics/ttl3_off.png";
img4off = new Image();
img4off.src = "pics/ttl4_off.png";
img5off = new Image();
img5off.src = "pics/ttl5_off.png";


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");
        }
}