var DDSPEED = 10;
var DDTIMER = 15;



// 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);
  
	}

}