private void listeDesSupportsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            ListingSupports formateur = new ListingSupports();

            formateur.MdiParent = this;
            formateur.Show();
        }
        private void nouvelleDistributionToolStripMenuItem_Click(object sender, EventArgs e)
        {
            ListingSupports formateur = new ListingSupports();

            formateur.MdiParent = this;
            formateur.Show();
        }