how to use a custom role provider in aspnet mvc via the webconfig

web.config

...
  <system.web>
    <customErrors mode="RemoteOnly" />
    <compilation debug="true" targetFramework="4.0" />
    <authentication mode="Forms">
      <forms loginUrl="~/Login" defaultUrl="/project/list" timeout="240" slidingExpiration="true" />
    </authentication>
    <profile defaultProvider="DefaultProfileProvider">
      <providers>
        <add name="DefaultProfileProvider" type="System.Web.Providers.DefaultProfileProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" />
      </providers>
    </profile>
    <membership defaultProvider="DefaultMembershipProvider">
      <providers>
        <add name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" />
      </providers>
    </membership>
    
    <!-- ZIA, LOOK DOWN HERE -->
    
    <roleManager defaultProvider="MyCustomRoleProvider" enabled="true">
      <providers>
        <clear />
        <add name="MyCustomRoleProvider" type="MyFullyQualifiedNamespace.MyCustomRoleProvider" />
      </providers>
    </roleManager>

...