function show (id) {
  if (document.getElementById)
    document.getElementById(id).style.visibility = "visible";
}

function hide (id) {
  if (document.getElementById)
    document.getElementById(id).style.visibility = "hidden";
}


function schriftGroesse () {
   for (var i = 0; i < document.getElementsByTagName("body").length; i++) {
    document.getElementsByTagName("body")[i].style.fontSize = "70%";
  }

}