I'm using the below code to receive the messages using serial port event handler. But it dosent receives any.I am not getting errors. The code breaks in "string msg = comport.Readline()" Am i doing something wrong ?

public partial class SerialPortScanner : Form
{
    private SerialPort comPort = new SerialPort();

    public SerialPortScanner()
    {
        InitializeComponent();
        comPort.Open();
        comPort.DataReceived += new SerialDataReceivedEventHandler(comPort_DataReceived);

    }


    void comPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        if (comPort.IsOpen == true)
        {
            string msg = comPort.ReadLine();
            MessageBox.Show(msg);
        }
    }
}