How do I send SMS messages using a C# desktop application?

{

                // Collect user input from the form and stow content into

                // the objects member variables
                string tb1, tb2;
                tb1 = textBox1.Text;
                tb2 = comboBox1.SelectedItem.ToString();

                mTo1 = tb1.Trim() + tb2.Trim();

                mFrom = (textBox2.Text).Trim();

                mSubject = (textBox3.Text).Trim();

                mMailServer = (textBox4.Text).Trim();

                mMsg = (textBox5.Text).Trim();

                // Within a try catch, format and send the message to

                // the recipient.  Catch and handle any errors.

                try
                {

                    MailMessage message = new MailMessage(mFrom, mTo1, mSubject, mMsg);

                    SmtpClient mySmtpClient = new SmtpClient(mMailServer);

                    mySmtpClient.UseDefaultCredentials = true;

                    mySmtpClient.Send(message);

                    MessageBox.Show("Message Sent");

                }

                catch (FormatException ex)
                {

                    MessageBox.Show(ex.StackTrace, ex.Message, MessageBoxButtons.OK, MessageBoxIcon.Error);

                }

                catch (SmtpException ex)
                {

                    MessageBox.Show(ex.StackTrace, ex.Message, MessageBoxButtons.OK, MessageBoxIcon.Error);

                }

                catch (Exception ex)
                {

                    MessageBox.Show(ex.StackTrace, ex.Message, MessageBoxButtons.OK, MessageBoxIcon.Error);

                }