function showBasics () {
  document.getElementById('basics').className = "menuActive";
  document.getElementById('enhanced').className = "menuNotActive";

  document.getElementById('b1').innerHTML = 'Einf&uuml;hrung in Perl<br />(als pdf, 458KB)';
  document.getElementById('b2').innerHTML = 'Arrays';
  document.getElementById('b3').innerHTML = 'Module';
  document.getElementById('b4').innerHTML = 'Perl-Styleguide';
  document.getElementById('b5').innerHTML = '';
  document.getElementById('b6').innerHTML = 'Sortierungen';
  document.getElementById('b7').innerHTML = '&Uuml;bergabeparameter';

  document.getElementById('b8').innerHTML = '';

  document.getElementById('e1').innerHTML = '';
  document.getElementById('e2').innerHTML = '';
  document.getElementById('e3').innerHTML = '';
  document.getElementById('e4').innerHTML = '';
  document.getElementById('e5').innerHTML = '';
  document.getElementById('e6').innerHTML = '';
  document.getElementById('e7').innerHTML = '';
  document.getElementById('e8').innerHTML = '';
} // showBasics

function showEnhanced () {
  document.getElementById('enhanced').className = "menuActive";
  document.getElementById('basics').className = "menuNotActive";

  document.getElementById('b1').innerHTML = '';
  document.getElementById('b2').innerHTML = '';
  document.getElementById('b3').innerHTML = '';
  document.getElementById('b4').innerHTML = '';
  document.getElementById('b5').innerHTML = '';
  document.getElementById('b6').innerHTML = '';
  document.getElementById('b7').innerHTML = '';
  document.getElementById('b8').innerHTML = '';

  document.getElementById('e1').innerHTML = 'Backtracing';
  document.getElementById('e2').innerHTML = 'Diverses zu CGI';
  document.getElementById('e3').innerHTML = 'MySql mit DBI';
  document.getElementById('e4').innerHTML = 'n&uuml;tzliche Einzeiler<br /> f&uuml;r LDIF-Dateien';
  document.getElementById('e5').innerHTML = 'Security';
  document.getElementById('e6').innerHTML = 'Tk';
  document.getElementById('e7').innerHTML = 'Win32';
  document.getElementById('e8').innerHTML = 'Win32::ODBC';
} // showEnhanced