var DDSPEED = 5;
var DDTIMER = 30;

// main function to handle the mouse events //
function ddMenu(id,dir) {
  var head = document.getElementById(id + '-ddheader');
  var cont = document.getElementById(id + '-ddcontent');
  if (cont)
  {
	  clearInterval(cont.timer);
	  if(dir == 1) 
	  {
		//alert(dir);
		cont.style.height = 10;
	    clearTimeout(head.timer);
	    if(cont.maxh && cont.maxh <= cont.style.height) 
		{
			//alert(cont.maxh);
			//alert(cont.offsetHeight);		
	      return;
		  
	    }
		else if(!cont.maxh) {
	      cont.style.display = 'block';
	      cont.style.height = 'auto';
	      cont.maxh = cont.offsetHeight;
	      cont.style.height = '0px';
		  	
	    }
		//alert(cont.maxh);
			//alert(cont.offsetHeight);
	    cont.timer = setInterval("ddSlide('" + id + "-ddcontent', 1)", DDTIMER);
		
	  } 
	  else 
	  {
	    head.timer = setTimeout('ddCollapse(\'' + id + '-ddcontent\')', 50);
	  }
	}
}

// collapse the menu //
function ddCollapse(id) {
  var cont = document.getElementById(id);
  cont.timer = setInterval("ddSlide('" + id + "', -1)", DDTIMER);
}

// cancel the collapse if a user rolls over the dropdown content //
function cancelHide(id) {
  var head = document.getElementById(id + '-ddheader');
  var cont = document.getElementById(id + '-ddcontent');
  clearTimeout(head.timer);
  clearInterval(cont.timer);
  if(cont.offsetHeight < cont.maxh) {
    cont.timer = setInterval("ddSlide('" + id + "-ddcontent', 1)", DDTIMER);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(id,dir) {
  var cont = document.getElementById(id);
  var currheight = cont.offsetHeight;
  
  var dist;
  //alert(dir);
  
  if(dir == 1) {
    dist = (Math.round((cont.maxh - currheight) / DDSPEED));
  } else {
    dist = (Math.round(currheight / DDSPEED));
  }
  if(dist <= 1) {
    dist = 1;
  }
  cont.style.height = currheight + (dist * dir) + 'px';
  cont.style.opacity = currheight / cont.maxh;
  cont.style.filter = 'alpha(opacity=' + (currheight * 100 / cont.maxh) + ')';
  if(((currheight < 2) && dir != 1) || ((currheight > (cont.maxh - 2)) && (dir == 1))) {
    clearInterval(cont.timer);
	if (dir == -1) cont.style.height = 1;
  }
}