function mainmenu(li_actief) {
  var m = document.getElementById("mainmenu");
  var mUp = '../';
  if (li_actief.toLowerCase() == 'home') {
    mUp = '';
  }
  m.innerHTML =
  '<table class="menutable" cellpadding="0" cellspacing="0">' +
  '<tr>' +
  '<td>' +
  '  <ul id="menu">' +
  '    <li id="li_home" class=""><a class="" href="' + mUp + 'index.html">Home</a></li>' +
  '    <li id="li_hobbies" class=""><a class="">Hobbies</a>' +
  '      <ul>' +
  '      <li class="eerste"><a href="' + mUp + 'hardlopen/index.html">Hardlopen</a></li>' +
  '      <li class=""><a href="' + mUp + 'motorrijden/index.html">Motorrijden</a></li>' +
  '      <li class=""><a href="' + mUp + 'sportschieten/index.html">Sportschieten</a></li>' +
  '      <li class=""><a href="' + mUp + 'kamperen/index.html">Kamperen</a></li>' +
  '      <li class=""><a href="' + mUp + 'langlauf/index.html">Langlaufen</a></li>' +
  '      <li class="laatste"><a href="' + mUp + 'nw/index.html">Nordic Walking</a></li>' +
  '      </ul>' +
  '    </li>' +
  '    <li id="li_werk" class=""><a class="">Werk</a>' +
  '      <ul>' +
  '      <li class="eerste"><a href="' + mUp + 'werk/index.html">Software Engineer</a></li>' +
  '      <li class=""><a href="' + mUp + 'cv_eelco_rem.pdf" target="_blank">CV</a></li>' +
  '      <li class="laatste"><a href="http://nl.linkedin.com/in/eelcorem" target="_blank">LinkedIn profile</a></li>' +
  '      </ul>' +
  '    </li>' +
  '    <li id="li_software" class="onderste"><a class="">Software</a>' +
  '      <ul>' +
  '      <li class="eerste"><a href="' + mUp + 'marktstreamer/index.html">MarktStreamer</a></li>' +
  '      <li class=""><a href="' + mUp + 'hardlopen/runcalc.html">HardloopCalculator</a></li>' +
  '      <li class=""><a href="' + mUp + 'javascript/sudoku.html">Sudoku Oplosser</a></li>' +
  '      <li class="laatste"><a href="' + mUp + 'javascript/konningenbord.html">Konningenbord</a></li>' +
  '      </ul>' +
  '    </li>' +
  '  </ul>' +
  '</td>' +
  '</tr>' +
  '</table>';
  var liDoc = document.getElementById("li_" + li_actief.toLowerCase());
  liDoc.setAttribute("class", "actief");
  if (li_actief.toLowerCase() == 'software') {
    liDoc.setAttribute("class", "ondersteactief");
  }
  var firstChild = liDoc.firstChild;
  var newnode = document.createElement("span");
  newnode.innerHTML = li_actief;
  liDoc.insertBefore(newnode, firstChild);
  liDoc.removeChild(firstChild);
}