/* 画像をランダムで表示 */
id=new Array("01", "02", "03", "04");

titleCount = 4;         //　画像の最大枚数
n = Math.floor(Math.random() * titleCount);

var token = getCookieValue("first_time_visit");


function imagesVariation(){

  var imagesVariationID;
  if (token != null){
		imagesVariationID = token;
	}else{
		setCookieValue("first_time_visit", id[n]);
		 imagesVariationID = id[n];
	}
	
	document.getElementById("banner").innerHTML = '<a href="/"><img src="/common/title/' + imagesVariationID +'/title.gif" /></a>';
	
	
	var menuSrc = '<div id="menu">'
			+ '<span class="news"><a href="/news/"><img src="/common/title/' + imagesVariationID + '/news.gif" /></a></span>'
			+ '<span class="works"><a href="/works/""><img src="/common/title/' + imagesVariationID + '/works.gif" /></a></span>'
 			+ '<span class="biography"><a href="/biography/"><img src="/common/title/' + imagesVariationID + '/bio.gif" /></a></span>'
 			+ '<span class="memo"><a href="/memo/"><img src="/common/title/' + imagesVariationID + '/memo.gif" /></a></span>'
 			+ '<span class="contact"><a href="/contact/"><img src="/common/title/' + imagesVariationID + '/contact.gif" /></a></span>'
 			+ '<span class="special"><a href="/special/"><img src="/common/title/' + imagesVariationID + '/special.gif" /></a></span>'
 			+'</div>';
 			
	document.getElementById("menu").innerHTML = menuSrc;
	
}


/* base functions */

function getCookieValue(name) {
	var cookieArray = document.cookie.split("; ");
	for (var i=0; i<cookieArray.length; i++) {
		var delimiterIdx = cookieArray[i].indexOf("=");
		var cookieName = cookieArray[i].substring(0, delimiterIdx);
		if (name == cookieName) {
			return cookieArray[i].substring(delimiterIdx + 1);
		}
	}
}

function setCookieValue(name, value) {
	setPre = new Date();
	// var cookieDays = 30;  保存日数
	// setPre.setTime(setPre.getTime() + (cookieDays*1000*24*3600));
	setPre.setTime(setPre.getTime() + (1000*2*3600));
	var expireDate = setPre.toGMTString();
	document.cookie = name + "=" + escape(value) + "; expires=" + expireDate + "; path=/";
}

/** execution body */
// titleVariation();
imagesVariation();