tomcat and security manager

[ni...@weblineindia.com]

i have an application in servlet and jsp
in directory format 
in /myapp

i have put  the /myapp in  c:\sites\myapp

i have created a host int server.xml file like

<Host name="10.0.0.1" >
           <Context path=""
                    docBase="c:\sites\myapp" />
 </Host>
now i start the tomcat in secure mode by giving 
command 

startup.bat  -security

now i request in browser 
like 
http://10.0.0.0/servlet/MyServlet

it gives error like 
java.security.AccessControlException: access denied (java.io.FilePermission C:\sites\myapp\web-inf\classes read)

i add lines in tomcat.policy

grant codeBase "file:C:\sites\myapp\-" {
  permission java.io.FilePermission "*", "read";
};

still geting same error 

any idea????

please help me

thanks in advance