Membership.ApplicationName problem

<membership defaultProvider="MembershipProvider">
      <providers>
        <clear/>
        <add name="MembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="connectionString" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="true" passwordFormat="Hashed" maxInvalidPasswordAttempts="99" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" passwordStrengthRegularExpression="" applicationName="/"/>
      </providers>
    </membership>
Membership.ApplicationName = "/";
MembershipUse ...