/// <summary>
/// Shows the new form
/// </summary>
/// <param name="sender">event sender</param>
/// <param name="e">event arguments</param>
private void ShowNewForm(object sender, EventArgs e)
{
Document.Document document = new Document.Document(640, 480);
// make it a child of this MDI form before showing it
document.MdiParent = this;
document.Text = "Document " + m_ChildFormNumber;
document.Show();
++m_ChildFormNumber;
}