/**
 * Class for navigation. I have used a class instead of functions,
 * to avoid double defination of functions. So all navi functions,
 * have to be called with Navi.xxx()
 *
 * ClickNavi has no state or instance methods. All methods are class methods (static).
 */
function Navi() {
}

Navi.setSelected = function(menuNum) {
	var childs = Navi.getLIChilds();
	for (var i=0; i<childs.length;i++) {
		var item = childs[i];
		var li = Navi.getSubLIElement(item);
		if (i == menuNum)
			li.className = "selected";
		else
			li.className = "";
	}
}



Navi.initNaviListener = function () {
	var childs = Navi.getLIChilds();
	for (var i=0; i<childs.length;i++) {
		var item = childs[i];
		item.onmouseover=function() {
			Navi.showSubMenu(this);
		}
	}
}

Navi.hideAllSubMenus = function () {
	var childs = Navi.getLIChilds();
	for (var i=0; i<childs.length;i++) {
		var item = childs[i];
		Navi.hideSubMenu(item);
	}
}

Navi.showSubMenu = function (ul) {
	Navi.hideAllSubMenus();

	var ul_sub = Navi.getSubULElement(ul);
	if (!ul_sub)
		return;
/*alert(ul.offsetWidth);
alert(ul.offsetLeft);*/

	if (ul_sub.style) {
		var left =ul.offsetLeft;/*+ul.offsetWidth/2;*/
		ul_sub.style.display = "block";
		/*left = left - ul_sub.offsetWidth/2;*/

		ul_sub.style.left = left+"px";
	}

	ul.onmouseout=function() {
		Navi.hideSubMenu(this);
	}
	ul_sub.onmouseover=function() {
		Navi.showSubMenu(this);
	}
	ul_sub.onmouseout=function() {
		Navi.hideSubMenu(this);
	}
}

Navi.hideSubMenu = function (ul) {
	var ul_sub = Navi.getSubULElement(ul);

	if (ul_sub && ul_sub.style)
		ul_sub.style.display = "none";
}

Navi.getLIChilds = function () {
	var liList = new Array();
	var menu = document.getElementById('navi');
	var ul = Navi.getSubULElement(menu);
	var childs = ul.childNodes;
	for (var i=0; i<childs.length;i++) {
		var item = childs.item(i);
		if (item.nodeName == "LI"){
			liList.push(item);
		}
	}
	return liList;
}

Navi.getSubLIElement = function (ul) {
	var sub_lis = ul.getElementsByTagName("li");
	return sub_lis[0];

}

Navi.getSubULElement = function (ul) {
	var sub_uls = ul.getElementsByTagName("ul");
	return sub_uls[0];
}