how to lock a system login after 3 failed attempts in vb6?

I already made security login that if failed 3 times the program will be terminated. However, I want to make a security login that will lock the system and the admin will be required to login instead.

Here's my code:

Dim nCnt As Integer
Dim nCnt2 As String

Private Sub cmdOk_Click()

    nUsername = "username ='" & txtUsername.Text & "'"
    npassword = txtPassword.Text

    If nCnt < 2 Then
        With adoLog.Recordset
            .MoveFirst
            .Find nUsername
            If .EOF Then
                MsgBox "Access Denied" & vbCrLf & "Please try again." & vbCrLf & vbCrLf & "Warning: You only have " & nCnt2 & " attempt.", vbCritical, "Terror"""
                nCnt = nCnt + 1
                nCnt2 = nCnt2 - 1
                Label7.Caption = nCnt2
                txtUsername.Text = ""
                txtPassword.Text = ""
                txtUsername.SetFocus
            Else
                If adoLog.Recordset.Fields("password").Value = npassword And adoLog.Recordset.Fields("flag").Value = 1 Then
                    Call Change_Flag
                    MsgBox "Access Granted"
                    cUser = adoLog.Recordset.Fields("name").Value
                    cPosition = adoLog.Recordset.Fields("position").Value

                    With adoHistory_Login.Recordset
                        .AddNew
                        .Fields("name").Value = cUser
                        .Fields("position").Value = cPosition
                        .Fields("time_login").Value = Time()
                        .Fields("date_login").Value = Date
                        .Fields("date_logout").Value = Date
                        .Update
开发者_如何学Go                        Me.Refresh
                        frmMain.Show
                        frmMain.SetFocus
                    End With

                    Unload Me
                    txtUsername.Text = ""
                    txtPassword.Text = ""
                Else
                    MsgBox "Access Denied" & vbCrLf & "Please try again." & vbCrLf & vbCrLf & "Warning: You only have " & nCnt2 & " attempt.", vbCritical, "Terror"""
                    nCnt = nCnt + 1
                    nCnt2 = nCnt2 - 1
                    Label7.Caption = nCnt2
                    txtUsername.Text = ""
                    txtPassword.Text = ""
                    txtUsername.SetFocus
                End If
            End If
        End With
    Else
        Call block
        End
    End If

End Sub

Private Sub Change_Flag()

    With adoLog.Recordset
        .Fields("flag").Value = 0
    End With

End Sub

Private Sub block()

    MsgBox "You already used all attempt." & vbCrLf & "This will terminate the application.", vbCritical, "Terror"

End Sub

Private Sub Form_Initialize()

    cmdOK.Enabled = False
    txtPassword.Enabled = False
    cmdRegister.Visible = False

    If adoLog.Recordset.RecordCount <> 0 Then
        cmdOK.Enabled = False
        txtPassword.Enabled = False
        txtUsername.Enabled = True
    Else
        cmdRegister.Visible = True
        txtUsername.Enabled = False
    End If

End Sub

Private Sub Form_Load()

    nCnt2 = 2
    Label7.Caption = nCnt2

End Sub

You will need to store an additional flag somewhere to indicate that login is denied and then check this flag before attempting the login. You will also need to store the account type and check to see if the account is allowed to log in even if this flag is set.

Are you wanting to lock out the full PC or the username that is being used?

Add a new column to the recordset for IsLocked and have it get set to true after the 3 logins (Make sure you provide some way for the admin to clear it back out though).

As soon as the username is used check IsLocked first before the password and kick it out immediately with the appropriate message.

Also, make sure you prevent the IsLocked from ever being set on the admin username.