var t=[];
    var i=[];
    //var md=0;
    //var mh=2;
    var md=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
    var mh=[2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2];
    var ddr=[100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100];
    var speed=8;

    window.onscroll = scroll;

function scroll(){
   UndoDropdowns(20,0);
}

    function DoDropdown(mid,no,ddo){
      ddr[mid]=ddo*16+11;   //line height of dropdown
      UndoDropdowns(no,mid);

      var p=getElementPosition('menuoption'+mid)

     //window.alert(mid+" "+no+" "+ddo);

      var dd=document.getElementById('dropdown'+mid);
      dd.style.position="absolute";
      dd.style.left=(p.left-4)+"px";
      dd.style.pixelLeft=(p.left-4);

      var vsb= f_scrollTop();

      dd.style.top=(p.top-vsb+20)+"px";
      dd.style.pixelTop= (p.top-vsb+20);

      movemenu(mid,1,no);
    }

    function UndoDropdowns(no,item){
      if (typeof(item) == 'undefined' ){
        item = 0;
      }

      for(mid=1;mid<=no;mid++){
        if (item!=mid){
          //stop movement
          md[mid]=0;
          clearInterval(t[mid]);
          //retract
          movemenu(mid,2,no);
        }
      }
    }

    function movemenu(mid,dir,no){
      //dir 1=down 2=up
      var s=document.getElementById('dropdown'+mid);
      if (md[mid]==0){
        t[mid]=setInterval("movemenu("+mid+","+dir+","+no+")",5);
        md[mid]=dir;
      }
      if (md[mid]==1){
        if (mh[mid]<ddr[mid]){
          mh[mid]=mh[mid]+speed;
          s.style.display="block";
        }else{
          md[mid]=0;
          clearInterval(t[mid]);
          //i[mid]=setTimeout("UndoDropdowns("+no+")",5000);
          mh[mid]=ddr[mid];
        }
      }
      if (md[mid]==2){
         if(mh[mid]>speed){
           mh[mid]=mh[mid]-speed ;
         } else {
           md[mid]=0;
           clearInterval(t[mid]);
           s.style.display="none";
         }
      }
      s.style.height=mh[mid]+ 'px';
    }


    function getElementPosition(elemID){
      var offsetTrail = document.getElementById(elemID);
      var offsetLeft = 0;
      var offsetTop = 0;
      while (offsetTrail){
        offsetLeft += offsetTrail.offsetLeft;
        offsetTop += offsetTrail.offsetTop;
        offsetTrail = offsetTrail.offsetParent;
      }
      if (navigator.userAgent.indexOf('Mac') != -1 && typeof document.body.leftMargin != 'undefined'){
        offsetLeft += document.body.leftMargin;
        offsetTop += document.body.topMargin;
      }
      return {left:offsetLeft,top:offsetTop};
    }

   function f_scrollTop() {
	  return f_filterResults (
		window.pageYOffset ? window.pageYOffset : 0,
		document.documentElement ? document.documentElement.scrollTop : 0,
		document.body ? document.body.scrollTop : 0
      );
    }

    function f_filterResults(n_win, n_docel, n_body) {
    	var n_result = n_win ? n_win : 0;
    	if (n_docel && (!n_result || (n_result > n_docel)))
    		n_result = n_docel;
    	return n_body && (!n_result || (n_result > n_body)) ? n_body : n_result;
     }