private void newChildToolStripMenuItem_Click(object sender, EventArgs e)
{
Form child = new MdiChild();
child.MdiParent = this;
child.WindowState = FormWindowState.Maximized;
child.Show();
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
MdiChild frm = new MdiChild();
frm.MdiParent = this;
frm.WindowState = FormWindowState.Maximized;
frm.Show();
}