expireperiod = 1000*60*60*24*365; // 有効期間( msec )
var expire = new Date();

// Cookie設定
function setCookie(name,value){
	expire.setTime((new Date()).getTime()+expireperiod);
	document.cookie = name + '=' + escape(value) + '; expires='+expire.toGMTString() + '; path=/';
	//alert(document.cookie);
}

// Cookie取得
function getCookie(name){
	//alert(document.cookie)
  var search = name + '=';
  if (document.cookie.length>0) {
    offset = document.cookie.indexOf(search);
    if (offset != -1){
      offset += search.length;
      end     = document.cookie.indexOf(';',offset);
      if(end == -1)
        end = document.cookie.length;
        return unescape(document.cookie.substring(offset,end));
    }
  }
  return null;
}

// Cookie消去
function clearCookie(name){
	expire.setTime((new Date()).getTime()-expireperiod);
	document.cookie = name + '= ; expires='+expire.toGMTString();
}