Private Sub TextBox1_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
Select Case TextBox1
Case ""
Me.TextBox1 = "0800": Me.TextBox2 = "1300"
Case "0800"
Me.TextBox1 = 1100: Me.TextBox2 = 1600
Case "1100"
Me.TextBox1 = 1000: Me.TextBox2 = 1700
Case "1000" 'facultatif
Me.TextBox1 = "": Me.TextBox2 = ""
End Select
Me.CommandButton1.SetFocus
End Sub