rails cookie missing for IE

I have a rails 2.1 application have the following code: class CookieController < ApplicationController   def index      extra = cookies["extra"]   end end

<%= "index" %> <script type="text/javascript">     set_cookie();     display_cookie();

    function readCookie(name) {         var nameEQ = name + "=";         var ca = document.cookie.split(';');         for(var i=0;i < ca.length;i++) {             var c = ca[i];             while (c.charAt(0)==' ') c = c.substring(1,c.length);             if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);         }         return null;     }     function createCookie(c_name,value,expiredays)     {         var exdate=new Date();         exdate.setDate(exdate.getDate()+expiredays);         document.cookie=c_name+ "=" +escape(value)+             ((expiredays==null) ? "" : ";expires="+exdate.toGMTString());     }     function set_cookie()     {         createCookie("extra","testbbb",100);         createCookie("another","testanother",100);         createCookie("ptheme","ccc",100);     }     function display_cookie()     {         alert(document.cookie)         var x = readCookie('ptheme')

    } </script>

The problem is that I can not see the cookie in controller when using ie, I can not see the cookie when use firefox. Any suggestion? Thanks in advance