Public Class F1
    Private Sub T1_TextChanged(sender As System.Object, e As System.EventArgs) Handles s.TextChanged
        If (s.Text <> "") Then
            OK.Enabled = True
        Else
            OK.Enabled = False
        End If
    End Sub

    Private Sub OK_Click(sender As System.Object, e As System.EventArgs) Handles OK.Click
        Me.Text = "Voyage : " & s.Text
        libre.Text = "Libre : " & N1.Value - N2.Value
        MsgBox("Départ :" & D1.Text & Environment.NewLine & "Arrivée :" & D2.Text & Environment.NewLine & "Durée :" & Dur.Text & " Jour(s)" & Environment.NewLine & "Places :" & N1.Text & Environment.NewLine & "Inscrits :" & N2.Text & Environment.NewLine & "Libres :" & N1.Value - N2.Value, MsgBoxStyle.Information, s.Text)
    End Sub

    Private Sub F1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        D1.Format = DateTimePickerFormat.Custom
        D2.Format = DateTimePickerFormat.Custom
        D1.CustomFormat = "dd/MM/yyyy"
        D2.CustomFormat = "dd/MM/yyyy"
        D2.MinDate = D1.Value
    End Sub

    Private Sub D1_ValueChanged(sender As System.Object, e As System.EventArgs) Handles D1.ValueChanged
        Dur.Text = DateDiff(DateInterval.Day, D1.Value, D2.Value)
        D2.MinDate = D1.Value
    End Sub

    Private Sub D2_ValueChanged(sender As System.Object, e As System.EventArgs) Handles D2.ValueChanged
        Dur.Text = DateDiff(DateInterval.Day, D1.Value, D2.Value)
    End Sub

    Private Sub N1_ValueChanged(sender As System.Object, e As System.EventArgs) Handles N1.ValueChanged
        libre.Text = "Libre : " & N1.Value - N2.Value
        N2.Maximum = N1.Value
    End Sub

    Private Sub N2_ValueChanged(sender As System.Object, e As System.EventArgs) Handles N2.ValueChanged
        libre.Text = "Libre : " & N1.Value - N2.Value
        N2.Maximum = N1.Value
    End Sub
End Class