var DDSPEED = 1;
var DDTIMER = 10;

// main function to handle the mouse events //
function ddMenu(id,d){
  var h = document.getElementById('ddheader-' + id);
  var c = document.getElementById('ddcontent-' + id);
  if(c == null){
      return;
  }
  c.className = 'withBorder';
  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('ddheader-' + id);
  var c = document.getElementById('ddcontent-' + id);
  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){
    dist = 1;
  }
  c.style.height = currh + (dist * d) + 'px';
  if((currh < 5 && d != 1) || (currh > (c.maxh - 2) && d == 1)){
      if(d != 1){
          c.style.height = '0px';
          c.className = 'withoutBorder';  
      }
    clearInterval(c.timer);
  }
}

// ---------------------------------------------------
// Return all elements of a specific class.
// Taken from an about.com tutorial.
// To apply styles to retrieved classes, you need to use a for loop.
// See the example below.
// ---------------------------------------------------


document.getElementsByClassName = function(cl) 
{
    var retnode = [];
    var myclass = new RegExp('\\b'+cl+'\\b');
    var elem = this.getElementsByTagName('*');
    for (var i = 0; i < elem.length; i++)
    {
        var classes = elem[i].className;
        if (myclass.test(classes))
            retnode.push(elem[i]);
    }
    return retnode;
}


/*
---------------------------------------------------
Functions inside the call to addLoadEvent will
fire when the page loads.  If there is already
a window.onload method on the page, then the
addLoadEvent function will create a brand new function
so that there is no conflict.
--------------------------------------------------- 
*/

function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  }
  else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}

addLoadEvent(function(){
});