function rollOverObject(name) {
    this.name    = name;
    this.off     = new Image ();
    this.off.src = "images/nav/" + name + ".gif";
    this.on      = new Image ();
    this.on.src  = "images/nav/" + name + "_over.gif";
    }

contact = new rollOverObject("contact");
services = new rollOverObject("services");
implementing = new rollOverObject("implementing");
casestudies = new rollOverObject("casestudies");
faqs = new rollOverObject("faqs");
links = new rollOverObject("links");
members = new rollOverObject("members");
home = new rollOverObject("home");

function rollOn(imageID) {
  document.images[imageID].src = eval(imageID + ".on.src");
}

function rollOff(imageID) {
  document.images[imageID].src = eval(imageID + ".off.src");
}