window.onload = function() {
	
	function getURLParam(name) {
		name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
		var regexS = "[\\?&]"+name+"=([^&#]*)";
		var regex = new RegExp( regexS );
		var results = regex.exec( window.location.href );
		if( results == null ) {
			return "";
		}
		else {
			return results[1];
		}
	}

	//class manipulation functions written by Binny V A (http://www.openjs.com/scripts/dom/class_manipulation.php)
	function hasClass(ele,cls) {
		return ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
	}
	function addClass(ele,cls) {
		if (!hasClass(ele,cls)) ele.className += " "+cls;
	}
	function removeClass(ele,cls) {
		if (hasClass(ele,cls)) {
			var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
			ele.className=ele.className.replace(reg,' ');
		}
	}
	
	var pageName = getURLParam("page");
	//array of menu items.
	menuItems = new Array();
	menuItems[0] = document.getElementById('menuHome');
	menuItems[1] = document.getElementById('menuAbilities');
	menuItems[2] = document.getElementById('menuCareers');
	menuItems[3] = document.getElementById('menuProjects');
	
	//array of pages
	contentPages = new Array();
	contentPages[0] = document.getElementById('contentHome');
	contentPages[1] = document.getElementById('contentAbilities');
	contentPages[2] = document.getElementById('contentCareers');
	contentPages[3] = document.getElementById('contentProjects');
	
	//url driven auto hide.
	if (!pageName == "") {
		for (i = 0; i < contentPages.length; i++) {
			if (contentPages[i].getAttribute("id").substring(7).toLowerCase() != pageName.toLowerCase()) {
				addClass(contentPages[i], "hidden");
			}
			else
			{
				removeClass(contentPages[i], "hidden");
			}
		}
	}
	else {
		for (i = 1; i < contentPages.length; i++) {
			addClass(contentPages[i], "hidden");
		}
		removeClass(document.getElementById('contentHome'), "hidden");
		
	}
	
	for (i = 0; i < menuItems.length; i++) {
		menuItems[i].onclick = changePage;
	}
	
	
	function changePage(e) {
		if (!e) var e = window.event;
	
		for (i = 0; i < contentPages.length; i++) {
			if(this.getAttribute("id").substring(4) == contentPages[i].getAttribute("id").substring(7)) {
				removeClass(contentPages[i], "hidden");
			}
			else {
				addClass(contentPages[i], "hidden");
			}
		}
	}
	
}