如何确定有多少人登陆Access数据库？

Sub ShowUserRosterMultipleUsers()
    Dim cn As New ADODB.Connection
    Dim cn2 As New ADODB.Connection
    Dim rs As New ADODB.Recordset
    Dim i, j As Long

    cn.Provider = "Microsoft.Jet.OLEDB.4.0"
    cn.Open "Data Source=c:/Northwind.mdb"

    cn2.Open "Provider=Microsoft.Jet.OLEDB.4.0;" _
    & "Data Source=c:/Northwind.mdb"

    ' The user roster is exposed as a provider-specific schema rowset
    ' in the Jet 4 OLE DB provider.  You have to use a GUID to
    ' reference the schema, as provider-specific schemas are not
    ' listed in ADO's type library for schema rowsets

    Set rs = cn.OpenSchema(adSchemaProviderSpecific, _
    , "{947bb102-5d43-11d1-bdbf-00c04fb92675}")

    'Output the list of all users in the current database.

    Debug.Print rs.Fields(0).Name, "", rs.Fields(1).Name, _
    "", rs.Fields(2).Name, rs.Fields(3).Name

    While Not rs.EOF
        Debug.Print rs.Fields(0), rs.Fields(1), _
        rs.Fields(2), rs.Fields(3)
        rs.MoveNext
    Wend

End Sub