var DDSPEED = 10;
var DDTIMER = 15;
var OFFSET = -2;
var ZINT = 100;

function ddMenu(id, d, offsetTop) {
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  if (c) {
      clearInterval(c.timer);
      if (d == 1) {
          clearTimeout(h.timer);
          c.style.display = 'block';
          if (c.maxh && c.maxh <= c.offsetHeight) { return }
          else if (!c.maxh) {
              c.style.left = (h.offsetWidth + OFFSET) + 'px';
              c.style.height = 'auto';
              c.maxh = c.offsetHeight;
              c.style.height = '0px';
              if (offsetTop != 0) c.style.top = offsetTop + 'px';
          }
          ZINT = ZINT + 1;
          c.style.zIndex = ZINT;
          c.timer = setInterval(function() { ddSlide(c, 1) }, DDTIMER);
      } else {
          h.timer = setTimeout(function() { ddCollapse(c) }, 50);
      }

  }
}

function ddCollapse(c){
  c.timer = setInterval(function(){ddSlide(c,-1)},DDTIMER);
}

function cancelHide(id){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  clearTimeout(h.timer);
  clearInterval(c.timer);
  if(c.offsetHeight < c.maxh){
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }
}

function ddSlide(c,d){
  var currh = c.offsetHeight;
  var dist;
  if(d == 1){
    dist = Math.round((c.maxh - currh) / DDSPEED);
  }else{
    dist = Math.round(currh / DDSPEED);
  }
  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 > (c.maxh - 2) && d == 1){
    clearInterval(c.timer);
  }else if(dist < 1 && d != 1){
    clearInterval(c.timer);
    c.style.display = 'none';
  }
}