Private Const JET_SCHEMA_USERROSTER = "{947bb102-5d43-11d1-bdbf-00c0­4fb92675}" 

Public Function LimitUsers(iNumber As Integer) As Boolean 
    'Compare the number of database users to a provided number, 
    'and if greater, shutdown the current database instance. 

    Dim rs As ADODB.Recordset 
    Dim iCtr As Integer 

    'Make sure the programmer allows at least one user. 
    If iNumber = 1 Then iNumber = 2 

    'Open the roster. 
    Set rs = CurrentProject.Connection.Open­Schema( _ 
            adSchemaProviderSpecific, , JET_SCHEMA_USERROSTER) 

    'rs.RecordCount doesn't work reliably here, so we need to cycle 
    'through the recordset to count the number of users. 
    Do While Not rs.EOF 
        iCtr = iCtr + 1 
        'If the number of users exceeds iNumber, then shutdown the 
        'current database instance. 
        If iCtr > iNumber Then GoTo Proc_Shutdown 
        rs.MoveNext 
    Loop 

    'Clean up 
    rs.Close 
    Set rs = Nothing 
    Exit Function 

Proc_Shutdown: 
    'Clean up before shutting down the current database instance. 
    rs.Close 
    Set rs = Nothing 
    Application.Quit 
End Function