var DDSPEED = 10;
var DDTIMER = 15;

// main function to handle the mouse events //
function ddMenu(id,d,dir){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  clearInterval(c.timer);
  if(d == 1){
    clearTimeout(h.timer);
    if(c.maxh && c.maxh <= c.offsetHeight){return}
    else if(!c.maxh){
	  if(dir == 'up') { c.style.top = '-' + c.offsetHeight + 'px'; }
      c.style.display = 'block';
      c.style.height = 'auto';
      c.maxh = c.offsetHeight;
      c.style.height = '0px';
	
    }
    c.timer = setInterval(function(){ddSlide(c,1,dir)},DDTIMER);
  }else{
    h.timer = setTimeout(function(){ddCollapse(c,dir)},50);
  }
}

// collapse the menu //
function ddCollapse(c,dir){
  c.timer = setInterval(function(){ddSlide(c,-1,dir)},DDTIMER);
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(id,dir){
  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,dir)},DDTIMER);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d,dir){
  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;
  }
  
 // alert('Dave');
  
  if(dir == 'up') { c.style.top = parseInt(c.style.top.replace('px','')) - parseInt(dist * d) + 'px'; }
  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);
  }
}