window.onload = function(){
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	showCategory('greeting');
	setTabClick('greetingNav','greeting');
	setTabClick('domeNav','dome');
	setTabClick('guildNav','guild');
	setTabClick('legendNav','legend');
	setTabClick('symbolNav','symbol');
};

function hide(elementId) {
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}
function show(elementId) {
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}
function showCategory(categoryName){
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	hide('dome'); 
	hide('guild'); 
	hide('legend'); 
	hide('symbol'); 
	show(categoryName);
	changeTab(categoryName);
}
function createTab() {
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	var content = document.getElementById("content");
	var primary = document.getElementById("primary");
	var history = document.getElementById("history");
	var nav = document.createElement("ul");
	nav.setAttribute('id','nav');
	nav.appendChild(createListItem('greetingNav','#greeting','理事長の挨拶'));
	nav.appendChild(createListItem('domeNav','#dome','にぎわいドーム構想'));
	nav.appendChild(createListItem('guildNav','#guild','振興組合の概要'));	
	nav.appendChild(createListItem('legendNav','#legend','昭和38年頃の商店街'));	
	nav.appendChild(createListItem('symbolNav','#symbol','復興のシンボル'));	
	primary.insertBefore(nav,history);
}
function createListItem(id,href,text) {
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	var a = document.createElement("a");
	var t = document.createTextNode(text);
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}
function setTabClick(listName,categoryName) {
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}
function changeTab(categoryName){
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}