if (document.images) {
  var sched_off = new Image();
  var sched_on = new Image();
  sched_off.src = "/portals/4/sched.png";
  sched_on.src = "/portals/4/schedover.png";

  var seminar_off = new Image();
  var seminar_on = new Image();
  seminar_off.src = "/portals/4/seminar.png";
  seminar_on.src = "/portals/4/seminarover.png";

  var career_off = new Image();
  var career_on = new Image();
  career_off.src = "/portals/4/career.png";
  career_on.src = "/portals/4/careerover.png";

  var ask_off = new Image();
  var ask_on = new Image();
  ask_off.src = "/portals/4/ask.png";
  ask_on.src = "/portals/4/askover.png";
}


function activate(imgName) {
  if (document.images) {
    if ( eval(imgName + "_on.complete") ) {
      document.images[imgName].src = eval(imgName + "_on.src");
    }
  }
}

function deactivate(imgName) {
  if (document.images) {
    if ( eval(imgName + "_off.complete") ) {
      document.images[imgName].src = eval(imgName + "_off.src");
    }
  }
}