window.onload = function(){
	createTab();
	hideHeading();
	showCategory('home');
	setTabClick('homeNav','home');
	setTabClick('profileNav','profile');
	setTabClick('menuNav','menu');
	setTabClick('serviceNav','service');
	setTabClick('faqNav','faq');
};

function hide(elementId) {
	document.getElementById(elementId).style.display = "none";
}
function show(elementId) {
	document.getElementById(elementId).style.display = "block";
}
function hideHeading() {
	hide('homeHeading');
	hide('profileHeading');
	hide('menuHeading');
	hide('serviceHeading');
	hide('faqHeading');
}
function showCategory(categoryName){
	hide('home');
	hide('profile');
	hide('menu');
	hide('service'); 
	hide('faq'); 
	show(categoryName);
	changeTab(categoryName);
}
function createTab() {
	var wrapper = document.getElementById("wrapper");
	var content = document.getElementById("content");
	var nav = document.createElement("ul");
	nav.setAttribute('id','nav');
	nav.appendChild(createListItem('homeNav','#home','Home'));
	nav.appendChild(createListItem('profileNav','#profile','Profile'));
	nav.appendChild(createListItem('menuNav','#menu','Menu'));
	nav.appendChild(createListItem('serviceNav','#service','Guide'));
	nav.appendChild(createListItem('faqNav','#faq','Blog'));	
	wrapper.insertBefore(nav,content);
}
function createListItem(id,href,text) {
	var li = document.createElement("li");
	var a = document.createElement("a");
	var t = document.createTextNode(text);
	li.setAttribute('id',id);
	a.setAttribute('href',href);
	a.appendChild(t);
	li.appendChild(a);
	return li;
}
function setTabClick(listName,categoryName) {
	var e = document.getElementById(listName).getElementsByTagName('a')[0];
	e.onclick = function(){
		showCategory(categoryName);
		return false;
	};
}
function changeTab(categoryName){
	var e = document.getElementById('nav');
	e.className = categoryName;
}