private void newOfferToolStripMenuItem_Click(object sender, EventArgs e)
 {
     Offer newOffer = new Offer("Nouvelle offre");
     newOffer.ShowDialog();
 }
 private void updateOfferToolStripMenuItem_Click(object sender, EventArgs e)
 {
     Offer updateOffer = new Offer("Modifier l'offre", "Modifier");
     updateOffer.ShowDialog();
 }
 private void deleteOfferToolStripMenuItem_Click(object sender, EventArgs e)
 {
     Offer deleteOffer = new Offer("Supprimer l'offre", "Supprimer", "");
     deleteOffer.ShowDialog();
 }