effacer le contenu d'un nombre spécifique de textbox en une seule fois

For Each elements As Control In Me.Controls
  If TypeOf (elements) Is TextBox And elements.TabIndex < 61 Then
    elements.Text = String.Empty
  End If
Next

Dim i As Byte
For i = 1 To 61
  If Me.Controls("Textbox" & i).Text <> "" Then Me.Controls("Textbox" & i).Text() = ""
Next

  Dim ctrl As Control
        For Each ctrl In Panel1.Controls
            If (ctrl.GetType() Is GetType(TextBox)) Then
                Dim txt As TextBox = CType(ctrl, TextBox)
                If txt.Text = "" Then
                    cmdclose.Enabled = False
                    MessageBox.Show("Vous devez remplir toutes les entrées!", "Paramétrer l'envoi de mail", MessageBoxButtons.OK, MessageBoxIcon.Error)
                    Exit Sub
                Else
                    cmdclose.Enabled = True
                End If
            End If
        Next