C#

catch(InvalidOperationException ex)
   {
   // TODO Log exception
   throw;
   }

public Orientation CurrentSplitterOrientation
{
    set { splitContainer1.Orientation = value; }

    get { return splitContainer1.Orientation; }
}

private SubForm1 subForm1 = new SubForm1();

private void Form1_Load(object sender, EventArgs e)
{
    subForm1.MdiParent = this;
    subForm1.Show();

}

private void button1_Click_1(object sender, EventArgs e)
{
    subForm1.MdiParent = null;
    subForm1.CurrentSplitterOrientation = Orientation.Vertical;
}

using (MailMessage mail = new MailMessage())
{
    mail.From = new MailAddress("me@mycompany.com");
    mail.To.Add("you@yourcompany.com");
    mail.Subject = "This is an email";
    
    AlternateView plainView = AlternateView.CreateAlternateViewFromString("This is my plain text content, viewable by those clients that don't support html", null, "text/plain");
    AlternateView htmlView = AlternateView.CreateAlternateViewFromString("<p>Here is an embedded image: <img src=\"cid:myimage\"></p>", null, "text/html");
    
    MemoryStream stream = new MemoryStream();
    theImage.Save(stream, ImageFormat.Jpeg);
    stream.Seek(0L, SeekOrigin.Begin);
    
    LinkedResource imageResource = new LinkedResource(stream, MediaTypeNames.Image.Jpeg);
    imageResource.ContentId = "myimage";
    htmlView.LinkedResources.Add(imageResource);
    
    mail.AlternateViews.Add(plainView);
    mail.AlternateViews.Add(htmlView);
    
    SmtpClient smtp = new SmtpClient("127.0.0.1");
    smtp.Send(mail);
}