function Menu(id) {
	if (!document.getElementById || !document.getElementsByTagName)
		return false;
	this.menu = document.getElementById(id);
	this.submenus = this.menu.getElementsByTagName("div");
	this.speed = 10;

}
Menu.prototype.init = function() {
	var mainInstance = this;
	for (var i = 0; i < this.submenus.length; i++)
		this.submenus[i].getElementsByTagName("span")[0].onclick = function() {
			mainInstance.toggleMenu(this.parentNode);
		};
	var links = this.menu.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++)
		if (links[i].href == parent.frames["main"].document.location.href) {
			links[i].className = "current";
			break;
		}


};


Menu.prototype.Update = function(){
	var links = parent.frames["nav"].document.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++)
  		if (links[i].href == parent.frames["main"].document.location.href) {
			links[i].className = "current";
		}
		else {
			links[i].className = "";
		}
};


Menu.prototype.toggleMenu = function(submenu) {
	if (submenu.className == "collapsed")
		this.expandMenu(submenu);
	else
		this.collapseMenu(submenu);
};
Menu.prototype.expandMenu = function(submenu) {
	var fullHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var links = submenu.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++)
		fullHeight += links[i].offsetHeight;
	var moveBy = Math.round(this.speed);
	
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight + moveBy;
		if (newHeight < fullHeight)
			submenu.style.height = newHeight + "px";
		else {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "";
		}
	}, 30);
        this.collapseOthers();

};
Menu.prototype.collapseMenu = function(submenu) {
	var minHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var moveBy = Math.round(this.speed * submenu.getElementsByTagName("a").length);
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight - moveBy;
		if (newHeight > minHeight)
			submenu.style.height = newHeight + "px";
		else {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "collapsed";
		}
	}, 30);
};
Menu.prototype.collapseOthers = function(submenu) {
	for (var i = 0; i < this.submenus.length; i++)
		if (this.submenus[i] != submenu && this.submenus[i].className != "collapsed")
			this.collapseMenu(this.submenus[i]);
};

Menu.prototype.collapseAll = function() {
	for (var i = 0; i < this.submenus.length; i++)
		if (this.submenus[i].className != "collapsed")
			this.submenus[i].className = "collapsed";
};