var isDOM = (document.getElementById ? true : false);
var isIE4 = ((document.all && !isDOM) ? true : false);
var isNS4 = (document.layers ? true : false);
var isNS = (navigator.appName == "Netscape");

var imgElement;
var menueElement;

var begin = 120;
var end = 220;

var state = 0;
var running = false;
var yMenuTo;
var offsetTop;

function getRef(id, isDOM, isIE4, isNS4) {
	if (isDOM) return document.getElementById(id);
	if (isIE4) return document.all[id];
	if (isNS4) return document.layers[id];
}


function dojob() {
         running = true;
         
         

        var destinationOpacity = (yMenuTo-begin)*(100/(end-begin));
         if (destinationOpacity<0) destinationOpacity = 0;
         if (destinationOpacity>100) destinationOpacity = 100;

         //ggfls Titel einblenden
        if (destinationOpacity<state) {
          // auf null blenden
          state -= 5;
          if (state<destinationOpacity) state = destinationOpacity;

          imgElement.style.filter = "Alpha(opacity="+state+")";
          imgElement.style.MozOpacity = state/100;
          if (state==0) imgElement.style.visibility="hidden";
          else imgElement.style.visibility="visible";

          if (state>destinationOpacity) setTimeout ("dojob()", 50);
          else running = false;
        }
        
        else if (destinationOpacity>state) {
          // auf null blenden
          state += 5;
          if (state>destinationOpacity) state = destinationOpacity;

          imgElement.style.filter = "Alpha(opacity="+state+")";
          imgElement.style.MozOpacity = state/100;
          if (state==0) imgElement.style.visibility="hidden";
          else imgElement.style.visibility="visible";

          if (state<destinationOpacity) setTimeout ("dojob()", 50);
          else running = false;
        }
        else if (destinationOpacity==state) {
           running = false;
        }


}


function move() {
        if (isNS4)
	{
                if (document.documentElement && document.documentElement.scrollTop) yMenuTo = document.documentElement.scrollTop;
                else if (document.body) yMenuTo = document.body.scrollTop;
                else yMenuTo= window.pageYOffset;
	}
	else if (isDOM)
	{
                if (document.documentElement && document.documentElement.scrollTop) yMenuTo = document.documentElement.scrollTop;
                else if (document.documentElement && document.documentElement.pageYOffset) yMenuTo = document.documentElement.pageYOffset;
                else if (document.body) yMenuTo = document.body.scrollTop;
                else yMenuTo= window.pageYOffset;
	}




         if (menueElement.offsetHeight+350 + yMenuTo > document.body.offsetHeight) {
            menueElement.style.position = "absolute";
            topp = (document.body.offsetHeight - (menueElement.offsetHeight+350));
         }
         else {
              topp = offsetTop;
              menueElement.style.position = "fixed";
         }
         if (topp < 0) topp = 0;
         menueElement.style.top = topp + "px";

         getRef('menue_left', isDOM, isIE4, isNS4).style.backgroundPosition = "0px -"+(menueElement.offsetHeight+350 + yMenuTo - document.body.offsetHeight)+"px";


        if (running==false) dojob();

}





function init() {
         /* Hier muss die Id des Elements angepasst werden!!! */
         imgElement = getRef('menue_logo', isDOM, isIE4, isNS4);
         menueElement = getRef('menue_links', isDOM, isIE4, isNS4);
         offsetTop = menueElement.offsetTop - 20;


         //window.attachEvent("onscroll", move, false);

}



window.onload = init;
window.onscroll = move;

document.onload = init;
//document.scroll = move;
document.scroll = move;