/// <summary>
/// Starts the to-point sub-dialog.
/// </summary>
void StartTo()
{
m_DialTo = new GetPointForm(this, "Finishing Point", Color.Cyan, true);
m_DialTo.Show();
m_DialTo.OnSelectPoint(m_To, false);
}
/// <summary>
/// Starts the from-point sub-dialog.
/// </summary>
void StartFrom()
{
m_DialFrom = new GetPointForm(this, "Starting Point", Color.DarkBlue, false);
m_DialFrom.Show();
m_DialFrom.OnSelectPoint(m_From, false);
}