window.addEvent('domready', function() {

  var ContentNaviLinks = $$('#content-navi a');
  var fadeContents = $$('div.fadeContent');

  var SetContent = function(el) {
    ContentNaviLinks.each(
      function(ele) {
        if ( ele.getProperty('rel') == el.getProperty('rel') ) { ele.addClass('current') }
        else { ele.removeClass('current') }
    } );
    fadeContents.each(
      function(ele) {
        fx = new Fx.Style(ele,'opacity').set(0);
        ele.setStyle('display','none');
    } );
    $(el.getProperty('rel')).setStyle('display','block');
    fx = new Fx.Style($(el.getProperty('rel')),'opacity',{duration:1000}).start(0,1);
  }


  // alle Content-DIVs ausblenden
  fadeContents.each(
    function(el) {
      fx = new Fx.Style(el,'opacity').set(0);
      el.setStyles( { position:'absolute', top:0, left:0, display:'none' } );
  } );


  // den einzelnen Menü-Links einen onClick-Event hinzufügen
  ContentNaviLinks.each(
    function(el) {
      el.addEvent('click',
        function(ev) {
          el.blur();
          ev = new Event(ev);
          SetContent(el);
          ev.stop();
  } ) } );
  
  
  // die "nach oben" Links entfernen
  $$('div.fadeContent a.top').each( function(el) { el.remove() } );


  // zufälliges Element der Menü-Links aktivieren
  // oder, falls gesetzt, den Wert im QueryString auslesen
  var i = new Array();
  ContentNaviLinks.each( function(el) { i.push(el.getProperty('rel')) } );
  var k = QueryString.substr(QueryString.search(/item=/)+5,2);
  if( i.contains(k) ) var e = k;
  else var e = i[$random(0,(i.length-1))];
  ContentNaviLinks.each( function(el) { if( el.getProperty('rel')==e ) SetContent(el) } );


} );