var DROPSPEED = 3;
var DROPTIMER = 3;


function findPosX(obj)
  {
    var curleft = 0;
    if(obj.offsetParent)
        while(1)
        {
          curleft += obj.offsetLeft;
          if(!obj.offsetParent)
            break;
          obj = obj.offsetParent;
        }
    else if(obj.x)
        curleft += obj.x;
    return curleft;
  }

  function findPosY(obj)
  {
    var curtop = 0;
    if(obj.offsetParent)
        while(1)
        {
          curtop += obj.offsetTop;
          if(!obj.offsetParent)
            break;
          obj = obj.offsetParent;
        }
    else if(obj.y)
        curtop += obj.y;
    return curtop;
  }




function dropDownMenu(id,d){
  var h = document.getElementById(id + '-drop_menu_header');
  var c = document.getElementById(id + '-drop_menu_content');
  var left_pos = findPosX(h);
  
  clearInterval(c.timer);
  if(d == 1){
    clearTimeout(h.timer);
    if(c.maxh && c.maxh <= c.offsetHeight){return}
    else if(!c.maxh){
      c.style.display = 'block';
      c.style.height = 'auto';
      c.style.left = left_pos;
      c.maxh = c.offsetHeight;
      c.style.height = '0px';
    }
    c.timer = setInterval(function(){menuSlide(c,1)},DROPTIMER);
  }else{
    h.timer = setTimeout(function(){ddCollapse(c)},1);
  }
}

function ddCollapse(c){
  c.timer = setInterval(function(){menuSlide(c,-1)},DROPTIMER);
}

function undoHiding(id){

  var h = document.getElementById(id + '-drop_menu_header');
  var c = document.getElementById(id + '-drop_menu_content');
  clearTimeout(h.timer);
  clearInterval(c.timer);
  if(c.offsetHeight < c.maxh){
    c.timer = setInterval(function(){menuSlide(c,1)},DROPTIMER);
  }
}

function menuSlide(c,d)
{
  var currh = c.offsetHeight;
  var dist;
  if(d == 1){
    dist = (Math.round((c.maxh - currh) / DROPSPEED));
  }else{
    dist = (Math.round(currh / DROPSPEED));
  }
  if(dist <= 1 && d == 1){
    dist = 1;
  }
  c.style.height = currh + (dist * d) + 'px';
  c.style.opacity = currh / c.maxh;
  c.style.filter = 'alpha(opacity=' + (currh * 100 / c.maxh) + ')';
  if((currh < 2 && d != 1) || (currh > (c.maxh - 2) && d == 1)){
    clearInterval(c.timer);
  }
}