// ... Quelle Dummy ...
  function bglayer(){}
// ... Ende Dummy ...

// Browserabhaengige Informationen
var  nn  = (navigator.appName == "Netscape") ? true : false
// Bildinformationen
var  imgURL = "grafiken/logo-yoyo.gif"
var  imgWidth = 80
var  imgHeight = 84
// Darstellungsinformationen
var  imgStep = 20         // Zeitintervall in ms
var  imgIntX = 200        // horizontales Intervall
var  imgIntY = 350        // vertikales Intervall
// Statusinformationen
var  imgIncX = 0
var  imgIncY = 0
// Zentrieren des Hintergrundbilds
function bgstep()
  {
  var iWidth = (nn ? innerWidth : Number(document.body.clientWidth))
  var iHeight = (nn ? innerHeight : Number(document.body.clientHeight))
  with(nn ? document.Bild : Bild)
    {
    // Platz fuer die Darstellung?
    if(imgWidth > iWidth || imgHeight > iHeight)
      {
      visibility = false
      return
      }
      // Koordinatenberechnung
      if(nn)
        {
        left = Math.floor((1 + Math.sin(imgIncX * 2 * Math.PI / imgIntX)) * ((innerWidth - imgWidth) / 2))
        top = Math.floor((1 + Math.cos(imgIncY * 2 * Math.PI / imgIntY)) * ((innerHeight - imgHeight) / 2))
        }
      else
        {
        style.left = Math.floor((1 + Math.sin(imgIncX * 2 * Math.PI / imgIntX)) * ((iWidth - imgWidth) / 2))
        style.top = Math.floor((1 + Math.cos(imgIncY * 2 * Math.PI / imgIntY)) * ((iHeight - imgHeight) / 2))
        }
      // Naechster Schritt
      imgIncX++
      imgIncY++
      imgIncX %= imgIntX
      imgIncY %= imgIntY
      visibility = true
    }
    setTimeout("bgstep()", imgStep)
  }

// Initialisierung der Darstellung
function bglayer()
  {
  var iWidth = (nn ? innerWidth : Number(document.body.clientWidth))
  var iHeight = (nn ? innerHeight : Number(document.body.clientHeight))
  with(nn ? document.Bild : Bild)
    {
    if(nn)
      {
      left = Math.floor((iWidth - imgWidth) / 2)
      top = Math.floor(iHeight - imgHeight)
      width = imgWidth
      height = imgHeight
      with(document)
        {
        open("text/html")
        write("<IMG SRC=\"" + imgURL + "\" " + "WIDTH=" + imgWidth + " " + "HEIGHT=" + imgHeight + " ALT=\"\">")
        close()
        }
      }
    else
      {
      style.left = Math.floor((iWidth - imgWidth) / 2)
      style.top = Math.floor(iHeight - imgHeight)
      style.width = imgWidth
      style.height = imgHeight
      innerHTML = "<IMG SRC=\"" + imgURL + "\" " + "WIDTH=" + imgWidth + " " + "HEIGHT=" + imgHeight + " ALT=\"\">"
      }
    setTimeout("bgstep()", imgStep)
    }
  }