Как запретить ввод одинаковых цифр?

Sub KeyPress(KeyAscii As Integer, tb As TextBox)
   Select Case KeyAscii
      Case 49 To 53, 8
          If KeyAscii <> 8 Then If Len(tb.Text) = 1 Then KeyAscii = 0
      Case Else
         KeyAscii = 0
   End Select
   Dim a: a = Array(Text1, Text2, Text3, Text4, Text5)
   For Each b In a
     If Not b Is tb Then If KeyAscii - 48 = Val(b.Text) Then KeyAscii = 0
   Next
End Sub
Private Sub Text1_KeyPress(KeyAscii As Integer)
   Call KeyPress(KeyAscii, Text1)
End Sub
Private Sub Text2_KeyPress(KeyAscii As Integer)
   Call KeyPress(KeyAscii, Text2)
End Sub
Private Sub Text3_KeyPress(KeyAscii As Integer)
   Call KeyPress(KeyAscii, Text3)
End Sub
Private Sub Text4_KeyPress(KeyAscii As Integer)
   Call KeyPress(KeyAscii, Text4)
End Sub
Private Sub Text5_KeyPress(KeyAscii As Integer)
   Call KeyPress(KeyAscii, Text5)
End Sub

Private Function check_data(stri As String) As Boolean
Dim dig(0 To 9) As Boolean
 
    For i% = 1 To Len(stri)
        a$ = Mid$(stri, i%, 1)
        If InStr("0123456789", a$) = 0 Then
           check_data = False
           Exit Function
        End If
        v% = Val(a$)
        If dig(v%) Then
           check_data = False
           Exit Function
        End If
        dig(v%) = True
    Next i%
    
    check_data = True
 
End Function
 
Private Sub Text1_Change()
 
        If Not check_data(Me.Text1) Then
 
           Me.Label1.Visible = True
           Me.Text1.ForeColor = QBColor(12)
           
        Else
        
           Me.Label1.Visible = False
           Me.Text1.ForeColor = QBColor(0)
           
        End If
        
End Sub