var DDSPEED = 5;
var DDTIMER = 10;

// 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.opacity = 0;
      c.style.filter = 'alpha(opacity=0)';

      c.style.display = 'block';
      c.style.height = 'auto';
      c.maxh = c.offsetHeight;
      c.style.height = '0px';

      c.currh = 0;
     }
    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 dist;
  
  if(d == 1){
    dist = (Math.round((c.maxh - c.currh) / DDSPEED));
  }else{
    dist = (Math.round(c.currh / DDSPEED));
  }
  if(dist <= 1 && d == 1){
    dist = 1;
  }
  c.currh += (dist * d);

  c.style.height = c.currh;
  c.style.opacity = c.currh / c.maxh * 0.9;
  c.style.filter = 'alpha(opacity=' + (c.currh * 90 / c.maxh) + ')';
  if((c.currh < 2 && d != 1) || (c.currh > (c.maxh - 2) && d == 1)){
    clearInterval(c.timer);
  }
}

// rollover //
function initRollovers() {
	if (!document.getElementById) return
	
	var aPreLoad = new Array();
	var sTempSrc;
	var aImages = document.getElementsByTagName('img');

	for (var i = 0; i < aImages.length; i++) {
		if (aImages[i].className == 'imgover') {
			var src = aImages[i].getAttribute('src');
			var ftype = src.substring(src.lastIndexOf('.'), src.length);
			var hsrc = src.replace(ftype, '_o'+ftype);

			aImages[i].setAttribute('hsrc', hsrc);
			
			aPreLoad[i] = new Image();
			aPreLoad[i].src = hsrc;
			
			aImages[i].onmouseover = function() {
				sTempSrc = this.getAttribute('src');
				this.setAttribute('src', this.getAttribute('hsrc'));
			}	
			
			aImages[i].onmouseout = function() {
				if (!sTempSrc) sTempSrc = this.getAttribute('src').replace('_o'+ftype, ftype);
				this.setAttribute('src', sTempSrc);
			}
		}
	}
}