function showpic(id){
  hideAll();  
  div = document.getElementById(id); 
  div.style.visibility = "visible";
  fadeIn(id,0);
}

function hidepic(id){
  div = document.getElementById(id); 
  div.style.visibility = "hidden";
}

function hideAll(){
  hidepic('amrum');
  hidepic('hiddensee');
  hidepic('borkum');
  hidepic('bochum');
  hidepic('oderwitz');
  hidepic('badduerrheim');
  hidepic('gais');
}

function fadeIn(objId,opacity) {
  if (document.getElementById) {
    obj = document.getElementById(objId);
    if (opacity <= 100) {
      setOpacity(obj, opacity);
      opacity += 10;
      window.setTimeout("fadeIn('"+objId+"',"+opacity+")", 30);
    }
  }
}

function setOpacity(obj, opacity) {
  opacity = (opacity == 100)?99.999:opacity;
  
  // IE/Win
  obj.style.filter = "alpha(opacity:"+opacity+")";
  
  // Safari<1.2, Konqueror
  obj.style.KHTMLOpacity = opacity/100;
  
  // Older Mozilla and Firefox
  obj.style.MozOpacity = opacity/100;
  
  // Safari 1.2, newer Firefox and Mozilla, CSS3
  obj.style.opacity = opacity/100;
}