var DDSPEED = 10;
var DDTIMER = 15;

// main function to handle the mouse events //
function ddMenu(id,d){
  var h = document.getElementById(id + 'MainDIV');  // title
  var c = document.getElementById(id);              // content
  c.style.display = 'block';
  clearInterval(c.timer);
  if(d == 1){
    clearTimeout(h.timer);
    if(c.maxh && c.maxh <= c.offsetHeight){return}
    else if(!c.maxh){
      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(id,h,c)},50);
  }
}

// collapse the menu //
function ddCollapse(id,h,c){
  //c.timer = setInterval(function(){ddSlide(c,-1)},DDTIMER);
  //h.timer = setInterval(function(){h.style.display='none';},DDTIMER);
  //c.timer = setInterval(function(){c.style.display='none';},DDTIMER);
  h.style.display='none';
  c.style.display='none';
  clearInterval(c.timer);
  clearInterval(h.timer); 
  //var badh = document.getElementById(id + 'MainDIV');  
  //badh.style.display='none';
  //debugMsg("bad Div: '" + id + "MainDIV' display: " + badh.style.display + "<br/>\n","add","debugDIV"); 
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(id){
  var h = document.getElementById(id + 'MainDIV');  // title
  var c = document.getElementById(id);              // content
  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);
  }
}