// preset menu timing //
var DDSPEED = 6;
var DDTIMER = 9;

// main function to handle the mouse events //
function ddMenu(id,d)
   {
    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)
        {
         c.style.display = 'block';
         c.style.height = 'auto';
         c.maxh = c.offsetHeight;
         c.style.height = '0px';
        }
       c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
     }
     else{h.timer = setTimeout(function(){ddCollapse(c)},50);}
   }

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

// cancel the collapse if a user rolls over the dropdown //
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);}
   }

// incrementally expand/contract the dropdown and change the opacity //
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 < 2 && d != 1) || (currh > (c.maxh - 2) && d == 1)){clearInterval(c.timer);}
   }