private void btnLivreManagement_Click(object sender, EventArgs e)
 {
     var frmCreateLivre = new CreateLivre(_frmMdi) {MdiParent = _frmMdi};
     frmCreateLivre.Show();
 }
 private void addBookToolStripMenuItem_Click(object sender, EventArgs e)
 {
     var frmCreateLivre = new CreateLivre(this);
     frmCreateLivre.MdiParent = this;
     frmCreateLivre.Show();
 }