var flag = false;

function imageLoad() {
 if (document.images) {
  img1on = new Image(); img1on.src = "img/link-home-on.gif";
  img2on = new Image(); img2on.src = "img/link-about-on.gif";
  img3on = new Image(); img3on.src = "img/link-services-on.gif";
  img4on = new Image(); img4on.src = "img/link-become-on.gif";
  img5on = new Image(); img5on.src = "img/link-signup-on.gif";
  img6on = new Image(); img6on.src = "img/link-contact-on.gif";
  return (flag = true);
 }
}

if (document.images) {
 img1off = new Image(); img1off.src = "img/link-home-off.gif";
 img2off = new Image(); img2off.src = "img/link-about-off.gif";
 img3off = new Image(); img3off.src = "img/link-services-off.gif";
 img4off = new Image(); img4off.src = "img/link-become-off.gif";
 img5off = new Image(); img5off.src = "img/link-signup-off.gif";
 img6off = new Image(); img6off.src = "img/link-contact-off.gif";
}

function rollIn(imgName) {
 if (document.images && (flag == true)) {
  document[imgName].src = eval(imgName + "on.src");
 }
}

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