var DDSPEED = 1;

var DDTIMER = 1;



// main function to handle the mouse events //

function ddMenu(id, d, pos) {

	var h = document.getElementById(id + '-header');

	var c = document.getElementById(id + '-sub');

	var n = document.getElementById('nav');

	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);		

		if(pos != undefined) {

			var w = document.getElementById('header').clientWidth;

			if(w > 1024) { w = Math.round((w - 1024)/2); } else { w = 0; }

			c.style.left = (w + pos) + 'px';

		}		

	} 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 + '-header');

	var c = document.getElementById(id + '-sub');

	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); }

}