function Fensterweite () {
  if (window.innerWidth) {
    return window.innerWidth;
  } else if (document.body && document.body.offsetWidth) {
    return document.body.offsetWidth;
  } else {
    return 0;
  }
}

function Fensterhoehe () {
  if (window.innerHeight) {
    return window.innerHeight;
  } else if (document.body && document.body.offsetHeight) {
    return document.body.offsetHeight;
  } else {
    return 0;
  }
}

function getFenster () {
  var fenster = new Array();
  fenster.width = Fensterweite();
  fenster.height = Fensterhoehe();
  return fenster;
}