In addition to what the others have told you, make sure you can handle the
case where the user has deleted their input from Textbox1:
Private Sub Textbox1_AfterUpdate()
If Nz(Me.Textbox1, vbNullString) ="Good" Then
Me.Textbox2="Bad"
End If
End Sub
And do you perhaps want to sete Textbox2 to nothing if Textbox1 isn't Good?
Private Sub Textbox1_AfterUpdate()
If Nz(Me.Textbox1, vbNullString) ="Good" Then
Me.Textbox2="Bad"
End If
Me.Textbox2=vbNullString
End If
End Sub
or, more simply
Private Sub Textbox1_AfterUpdate()
Me.Textbox2=IIf(Nz(Me.Textbox1, vbNullString) ="Good", _
"Bad", vbNullString)
End Sub