var actMenuItem = null;

function showMenuItem(target) {
	if(target!=actMenuItem) {
		if(actMenuItem==null) {
			actMenuItem = document.getElementById('submenu_opened');
		}
		if(actMenuItem!=null) {
			hideMenuItem(actMenuItem);
		}
		var ul = target.getElementsByTagName('ul');
		ul[0].style.display = 'block';
		ul[0].style.height = 'auto';
		var h = ul[0].clientHeight;
		ul[0].style.height = 0;
		var navigationSlide = new Fx.Tween(ul[0]).start('height', 0, h);
		actMenuItem = target;
	}
}

function hideMenuItem(target) {
	var ul = target.getElementsByTagName('ul');
	ul[0].style.height = 'auto';
	var h = ul[0].clientHeight;
	var navigationSlide = new Fx.Tween(ul[0]);
	navigationSlide.addEvents({
	    'complete': function() {
    	  //  ul[0].style.display = 'none';
	    }
	});
	navigationSlide.start('height', h, 0);
}