private void btnclient_Click(object sender, EventArgs e)
{
//lancer form client
Form_client f1 = new Form_client();
f1.Show();
}
private void clientToolStripMenuItemBBB_Click(object sender, EventArgs e)
{
Form_client f2 = new Form_client();
f2.TopLevel = false;
this.panel1.Controls.Add(f2);
f2.FormBorderStyle = FormBorderStyle.None;
f2.Top = 0;
f2.Left = 0;
f2.Size = f2.ClientSize;
f2.Dock = DockStyle.Fill;
f2.BringToFront();
f2.Show();
this.Text = "Client";
}