window.onload = function(){
	hideHeading();
	showContents('information');
	setTabClick('navInformation','information');
	setTabClick('navImage','image');
	setTabClick('navEvent','event');
};

function hideHeading() {
	hide('informationHeading');
	hide('imageHeading');
	hide('eventHeading');
}

function showContents(contentName){
	hide('information'); 
	hide('image'); 
	hide('event'); 
	show(contentName);
	chengeTabs(contentName);
}
function chengeTabs(contentName){
	var e = document.getElementById('nav');
	e.className = contentName;
}

function setTabClick(li,div) {
	var e = document.getElementById(li).getElementsByTagName('a')[0];
	e.contents = div;
	e.onclick = function(){
		showContents(this.contents);
		return false;
	};
}

function hide(elementId) {
	document.getElementById(elementId).style.display = "none";
}
function show(elementId) {
	document.getElementById(elementId).style.display = "";
}