// Geschwindigkeit des Scrollen
  var speed = 1;

  // Feste Werte NICHT VERAENDERN!!!
  var mousex;
  var mousey;
  var richtung = 0;
  var nrichtung;
  var apos = 0;
  var noscroll = 1;
  var wolkenpos = 0;
  var skylinepos = 0;

  // Scrollen
  function scrollBG() {
    // Richtung checken
    if (mousex > apos) {
      nrichtung = 1;
      noscroll = 0;
    } else if (mousex < apos) {
      nrichtung = -1;
      noscroll = 0;
    } else {
      noscroll = 1;
    }
    // Scrollen wenn nicht mehr alte Pos
    if (noscroll == 0) {
      scrolling();
    }
    // Richtung umdrehen
    if (nrichtung != richtung) {
      richtung = nrichtung;
    }
    // Aktuelle Pos als Mitte
    apos = mousex;
  }

  function scrolling() {
    // Alle Elemente holen
    var wolken = document.getElementById("wolken");
    var skyline = document.getElementById("skyline");
    // Speed halbieren
    mspeed = (speed * richtung);
    // Wolken verschieben
    wolkenpos = parseFloat(wolkenpos + mspeed);
    wolken.style.backgroundPosition = wolkenpos + "px 0px";
    // Skyline verschieben
    skylinepos = parseFloat(skylinepos + (mspeed * 2));
    skyline.style.backgroundPosition = skylinepos + "px 280px";
  }

  // XY auslesen
  function getXY(e) {
    if(!e) e = window.event;
    var body = (window.document.compatMode && window.document.compatMode == "CSS1Compat") ?
    window.document.documentElement : window.document.body || null;
    mousey = e.pageY ? e.pageY : e.clientY + body.scrollTop;
    mousex = e.pageX ? e.pageX : e.clientX + body.scrollLeft;
    // Scrollen starten
    scrollBG();
  }

  // Initialisieren
  function init() {
    if (window.event) {
      if (document.captureEvents){
        document.captureEvents(Event.MOUSEMOVE);
      } else {
        window.captureEvents(Event.MOUSEMOVE);
      }
    }
    document.onmousemove = getXY;
  }

  // Starten
  init();