var mpa = {

	hidden: false,
	toggleLink: null,

	init: function() {
		mpa.toggleLink = document.createElement("a");
		mpa.toggleLink.href = "#";
		var t = document.createTextNode(mpa.getLinkText());
		mpa.toggleLink.appendChild(t);
		mpa.toggleLink.onclick = mpa.toggle;
		mpa.list = mpa.getElementsByClass("mpaindex", null, "li"); 
		var p = document.createElement("p");
		p.appendChild(mpa.toggleLink);
		document.getElementById("mpaLead").appendChild(p);
	},

	getLinkText:function() {
		if (mpa.hidden) {
			return "Show index";
		}
		else {
			return "Hide index";
		}
	},

	toggle: function() {
		mpa.hidden = !mpa.hidden;
		mpa.toggleLink.innerHTML = mpa.getLinkText();
		for (i = 0; i < mpa.list.length; i++) {
			if (!mpa.hidden) {
				mpa.list[i].className = "mpaindex";
			}
			else {
				mpa.list[i].className = "hidden";
			}
		}
	},

	getElementsByClass: function (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;
	}

}

YAHOO.util.Event.addListener(window, "load", mpa.init);