window.onload = function(){
	createTab();
	showCategory('buisiness');
	setTabClick('ippanNav','ippan');
	setTabClick('shinbunNav','shinbun');
	setTabClick('kyoudoNav','kyoudo');
	setTabClick('shichoukakuNav','shichoukaku');
	setTabClick('referenceNav','reference');
	setTabClick('buisinessNav','buisiness');
	setTabClick('lawNav','law');	
	setTabClick('tenjiNav','tenji');	
	setTabClick('jishuuNav','jishuu');	
	setTabClick('sougouNav','sougou');		
};



function createTab() {
	var side_menu = document.getElementById("side_menu");
	var emp = document.getElementById("emp");
	var nav = document.createElement("ul");
	nav.setAttribute('id','annai_nav');
	nav.appendChild(createListItem('ippanNav','#ippan','一般図書を利用する'));
	nav.appendChild(createListItem('shinbunNav','#shinbun','新聞雑誌を利用する'));
	nav.appendChild(createListItem('kyoudoNav','#kyoudo','郷土資料を利用する'));
	nav.appendChild(createListItem('shichoukakuNav','#shichoukaku','視聴覚資料・音楽図書を利用する'));
	nav.appendChild(createListItem('referenceNav','#reference','調べ物をする'));
	nav.appendChild(createListItem('buisinessNav','#buisiness','ビジネス図書を利用する'));
	nav.appendChild(createListItem('lawNav','#law','法律図書を利用する'));
	nav.appendChild(createListItem('tenjiNav','#tenji','展示を見る'));
	nav.appendChild(createListItem('jishuuNav','#jishuu','飲食・自習する'));		
	nav.appendChild(createListItem('sougouNav','#sougou','総合学習で利用する'));				
	side_menu.insertBefore(nav,emp);
}

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 showCategory(categoryName){
	hide('ippan'); 
	hide('shinbun'); 
	hide('kyoudo'); 
	hide('shichoukaku');
	hide('reference');
	hide('buisiness');
	hide('law');
	hide('tenji');
	hide('jishuu');
	hide('sougou');
	show(categoryName);
	changeTab(categoryName);
}

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

function show(elementId) {
	document.getElementById(elementId).style.display = "block";
}

function changeTab(categoryName) {
	var e = document.getElementById('annai_nav');
	e.className = categoryName;
}

function setTabClick(listName,categoryName) {
	var e = document.getElementById(listName).getElementsByTagName('a')[0];
	e.onclick = function(){
		showCategory(categoryName);
		return false;
	};
}