public MainForm(string filename)
{
InitializeComponent();
DocumentForm childForm = new DocumentForm(filename);
childForm.MdiParent = this;
childForm.WindowState = FormWindowState.Maximized;
childForm.Show();
}
private void ShowNewForm(object sender, EventArgs e)
{
DocumentForm childForm = new DocumentForm();
childForm.MdiParent = this;
childForm.WindowState = FormWindowState.Maximized;
childForm.Text = "Window " + childFormNumber++;
childForm.Show();
}