Empêcher la saisie de 2 tirets successifs dans une textbox

Private Sub TextBox1_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger) 'à l'appui sur un touche dans la TetxBox1
'si le dernier caractère de la Tetxbox1 est un tiret et
'si la toucle appuyée est le tiret, la touche appuyée devient [Backspace] (=efface le tiret)
If Right(TextBox1.Value, 1) = "-" And KeyAscii = 45 Then KeyAscii = 8
End Sub

Private Sub TextBox1_Change()
 mem = TextBox1.SelStart
 a = TextBox1
 b = InStr(a, "--")
   
 While b > 0
   a = Mid(a, 1, b - 1) & Mid(a, b + 1)
   mem = mem - 1
   ok = True
   b = InStr(a, "--")
 Wend
 If ok = True Then
  TextBox1 = a
  On Error Resume Next
  TextBox1.SelStart = mem
 End If
End Sub

Private Sub TextBox1_Change()

    Dim i As Integer, h As Integer, Chaine As String, Compteur As Integer
    Dim Obj As Object
    
    Set Obj = TextBox1
    Chaine = Obj.Value
    
    For i = 1 To Len(Obj.Value)
        
        Compteur = 0
        If Mid(Chaine, i, 1) = "-" Then
            
            For h = i To Len(Obj.Value)
                
                If Mid(Chaine, h, 1) = "-" Then
                    
                    Compteur = Compteur + 1
                    
                Else
                
                    Exit For
                
                End If
            
            Next h
        
        Chaine = Mid(Chaine, 1, i) & Mid(Chaine, i + Compteur, Len(Chaine))
        End If
    
    Next i
    
    Application.EnableEvents = False
    Obj.Value = Chaine
    Application.EnableEvents = True

End Sub