d_url=new Array();
var un=0,n,bango=0;
d_url[un++]="http://shopping24.web.infoseek.co.jp/top-pet.html";
http://shopping24.web.infoseek.co.jp/cm/11.html 
n=d_url.length
document.write('<IFRAME id="top-pet" style="width:720;height:110;" frameborder=0" scrolling=no></IFRAME>');
bango=Math.floor(Math.random()*n);
document.getElementById("top-pet").src=d_url[bango];
<!-- 
//--Copyright (C) Miyake_kobo.--
//-->