childElements = new Array();
parentElements = new Array();
currentElementID = '';

function registerNavigationItems() {
	elements = getElementsByClass('nav-item');
	
	for(var i = 0; i < elements.length; i++) {
		childElement = el('sub' + elements[i].id);
		parentElement = elements[i];
	
		childElements[elements[i].id] = childElement;
		parentElements[elements[i].id] = parentElement;
		
		elements[i].onmouseover = function() {
			for(j in elements) {
				if(elements[j].id != this.id) {
					childElements[elements[j].id].style.display = 'none';
					parentElements[elements[j].id].className = parentElements[elements[j].id].className.replace(' over', '');
				}
			}
			childElements[this.id].style.display = 'block';
			parentElements[this.id].className += ' over';
			currentElementID = this.id;
		}
	}
}

function setNoSubnav() {
	if(currentElementID != '') {
		childElements[currentElementID].style.display = 'none';
		parentElements[currentElementID].className = parentElements[currentElementID].className.replace(' over', '');		
	}
}

function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	}
	else {
		window.onload = function() {
			oldonload();
			func();
		}
	}
}

function getElementsByClass(searchClass, node, tag) {
	var classElements = new Array();
	if (node == null)
		node = document;
	if (tag == null)
		tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\s)"+searchClass+"(\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}

function el(id) {
	return document.getElementById(id);
}

addLoadEvent(registerNavigationItems);