function setNav(nav) {
  document.getElementById("linkHome").setAttribute('class','');
  document.getElementById("linkHome").setAttribute('className',''); //IE
  document.getElementById("linkFeatures").setAttribute('class','');
  document.getElementById("linkFeatures").setAttribute('className',''); //IE
  document.getElementById("linkSuccess").setAttribute('class','');
  document.getElementById("linkSuccess").setAttribute('className',''); //IE
  if (nav == "home") {
    document.getElementById("linkHome").setAttribute('class','curr');
    document.getElementById("linkHome").setAttribute('className','curr'); //IE
    return true;
  }
  if (nav == "features") {
    document.getElementById("linkFeatures").setAttribute('class','curr');
    document.getElementById("linkFeatures").setAttribute('className','curr'); //IE
    return true;
  }
  if (nav == "success") {
    document.getElementById("linkSuccess").setAttribute('class','curr');
    document.getElementById("linkSuccess").setAttribute('className','curr'); //IE
    return true;
  }
  return true;
}