var bIE = (document.all) ? true : false;
var nav = (document.layers) ? true : false;
var dom = (document.getElementById && !document.all) ? true : false;
var ypos,yyy=-1000,iActive=1,sName='layr';
if (nav || dom) {
  document.captureEvents(Event.MOUSEMOVE);
  document.onmousemove=get_mouse;
}

function start() {
// Alle Layer verstecken
  for (a = 1; a < 11; a++){
    if (bIE)
      document.all[sName+a].style.visibility = "hidden";
    else if (nav)
      document.layers[sName+a].visibility = "hide";
    else if (dom)
      document.getElementById([sName+a]).style.display = "none";
  }
}

var iActive = 0;
function show(iNewLayer,iLevel){
//Alte Felder hidden setzten
  if (iActive != 0) {
    if (bIE) 
      document.all[sName + iActive].style.visibility = 'hidden';
    else if (nav)
      document.layers[sName + iActive].visibility = "hide";
    else if (dom)
      document.getElementById([sName + iActive]).style.display = "none";
  }
//Neue Felder einschalten
  if (iNewLayer > 0) {
    if (bIE) {
      get_mouse();
      eval (sName+iNewLayer+".style.top = '"+ypos+"'");
      document.all[sName + iNewLayer].style.visibility = 'visible';
    }
    else if (nav) {
      eval ("document."+sName+iNewLayer+".top = '"+ypos+"'");
      document.layers[sName + iNewLayer].visibility = "show";
      window.captureEvents(Event.MOUSEUP);
      window.onmouseup=klick;
    }
    else if (dom) {
      document.getElementById([sName + iNewLayer]).style.display = "block";
      document.getElementById([sName + iNewLayer]).style.top = ypos;
    }
  }
  iActive = iNewLayer;
}

function get_mouse(e){
  if (bIE){
    var yCo = event.y;
    var scrollen = document.body.scrollTop;
  }
  else if (nav || dom) 
    var yCo = e.pageY;
  (scrollen)?ypos = yCo + scrollen - 15:ypos = yCo - 15;
}

function klick(aha){
  show(0,0);
}