var DDSPEED = 10;
var DDTIMER = 15;

// toggle expand/collapse //

function toggle(ident){
var h = document.getElementById(ident + '-ddcontent');
if(h.style.height == 0 || h.style.height == '0px' ){
	ddMenu(ident,1);
	} else {
	ddMenu(ident,-1);
	}
}

// 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,h)},DDTIMER);
  }else{
    h.timer = setTimeout(function(){ddCollapse(c,h)},50);
  }
}

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

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d,h){
  var currh = c.offsetHeight;
  var dist;
  if(d == 1){
    dist = (Math.round((c.maxh - currh) / DDSPEED));
	h.style.backgroundColor = '#297bbb';
	h.style.backgroundImage = 'url(images/arrow_on.gif)';
	
  }else{
    dist = (Math.round(currh / DDSPEED));
	h.style.backgroundColor = '#3d97cf';
	h.style.backgroundImage = 'url(images/arrow_off.gif)';
  }
  if(dist <= 1 && d == 1){
    dist = 1;
  }

if(dist < 1 && d != 1){

  c.style.height = '0px';} else {
  c.style.height = currh + (dist * d) + 'px';}
if(d == 1)  { c.style.opacity = 1; } else if (d != 1  && currh<1) { c.style.opacity = 0; }
  c.style.filter = 'alpha(opacity=' + (currh * 100 / c.maxh) + ')';
  if((currh < 2 && d != 1) || (currh > (c.maxh - 2) && d == 1)){

    clearInterval(c.timer);
  }
}