Problem in AT commands

See more:

C#

.NET

Mobile

Hi, anyone please help me.
I have a problem in my C# code to connect my system to the gsm modem serial port:

 private void Form1_Load(object sender, EventArgs e)
        {
            try
            {


                p.PortName = "COM9";
                p.BaudRate = 460800;
                p.DataBits = 8;
                p.StopBits = StopBits.One;
                p.Parity = Parity.None;
                p.ReadTimeout = 300;
                p.WriteTimeout = 300;
                p.Open();
                p.DtrEnable = true;
                p.RtsEnable = true;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            
            p.Write("AT\r\n");
            String s1 = p.ReadLine();
            if (s1.Equals ("OK"))
            {
                MessageBox.Show("Port is connected");
            }
            else
                MessageBox.Show("Port is not connected");  
        }

        private void button1_Click(object sender, EventArgs e)
        {
           // p.write("");

            p.Write("at+cmgf=1\r\n");
            p.Write("at+cmgs=\"+919842798108\"\r\n");
            
            p.Write("Test message ");
            SendKeys.Send("^(z)");
           
            String s2 = p.ReadLine();
            if (s2.Equals("OK"))
            {
                MessageBox.Show("Message Sent");
            }
            else
                MessageBox.Show("Message not sent");
        }
    }
}

Every time it shows "port is not connected".
Please find the error in my code. And how to connect my gsm modem port with my system?

Hey. Is there any way without using MScomm?
I am using Visual studio 2008.
Please reply me.