simple login program -

I'm trying to the login program,
i want the user to only be allowed 3 chances of retry(vbretry),the the program sholud exit,
how to i go about it...here is the code
i have 2 text box for txtuser and txtpass and a button.
help is appreciated
thks



Private Sub cmdLogin_Click()


Dim password As String
Dim username As String
Dim attempt, i, retry As Integer


Me.txtuser.Text = username
Me.txtpass.Text = passowrd
username = "admin"
password = "secret"


Me.txtuser.SetFocus
If username = "admin" And passoword = "secret" Then
MsgBox "Welcome Access Granted", vbOKCancel, "Welcome to Llyods Bank"
Else

retry = MsgBox("Intruder Alert", vbRetryCancel + vbCritical, "Intruder Alert")

If retry = 4 Then
attempt = attempt + 1
Loop Until attempt = 3
Me.txtuser.SetFocus

End If

End If
End Sub


Private Sub Form_Load()
attempt = 0
End Sub


where to place the loop ...i don't know????