webconfig location path

Hi,

I am storing roles in sqlserver , and i given permissions as below in web.config



<roleManager enabled="true" defaultProvider="AspNetSqlRoleProvider">
      <providers>
        <clear/>
        <add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />      
      </providers>
    </roleManager>
    </system.web>


  <location path="~/Admin/abc.aspx">
    <system.web>
      <authorization>
        <allow users="*"/>
        <deny users="jack"/>      
      </authorization>      
    </system.web>    
  </location>

Here i am deny  jack  not to access the abc.aspx file, but it is allowing him to

 access that file

can you please guide me what are the steps i need to do more.