角色管理方面的问题


<roleManager defaultProvider="SqlProvider" enabled="true" cacheRolesInCookie="true" cookieTimeout="30" cookieName="aspnetRoles" cookiePath="/" cookieRequireSSL="false" cookieSlidingExpiration="true" cookieProtection="All">
        <providers>
          <add name="SqlProvider" type="System.Web.Security.SqlRoleProvide" connectionStringName="northWindConn" applicationName="/" />
       </providers>
     </roleManager>提示错误：未能加载类型“System.Web.Security.SqlRoleProvide”。 还有<membership>字节里面的也和这个差不多，请问如何解决？