function hideAllSectionsExceptFirst() {
  $('.section').not(':first-child').hide();
  $('ul#submenu li a').removeClass('selected');
  $('ul#submenu li:first a').addClass('selected');
}

function hideAllSections() {
  $('.section').hide();
  $('ul#submenu li a').removeClass('selected');
}

function showSection (s) {
  var section = $('#' + s);
  if (!section.is(':visible')) {
    hideAllSections();
    section.show('fast');
    $('#m' + s).addClass('selected');
  }

  return false;
}