var _banner_num = 2; //バナーの種類数
var _brand= "sn";
var _r = Math.floor(Math.random() *_banner_num);
var _url = "http://www.nissinfoods.jp/?xadid=";
var _xadid=["0129N","0130N","0131N","0132N"];


var _banner  = '<a href='+ _url + _xadid[_r] +' target="_blank"><img src="http://www.nissinfoods.jp/banner/images/'+ _brand +'_'+ (_r+1) +'.gif" alt="麺好き集まれ！NOODLE+" width="153" height="38" /></a>';
document.write(_banner);