Get Data From Serial Port vb.net

Question

I want to read the data from SERIAL PORT in text format and want to write it to the notepad I have used the below code to get data but still not working Anyone has any Idea For the same Please Update your help will be appreciated.

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        ReceiveSerialData()
    End Sub

    Function ReceiveSerialData() As String
        ' Receive strings from a serial port.
        Dim returnStr As String = ""

        Dim com1 As IO.Ports.SerialPort = Nothing
        Try
            com1 = My.Computer.Ports.OpenSerialPort("COM3")
            com1.ReadTimeout = 10000
            Do
                Dim Incoming As String = com1.ReadLine()
                If Incoming Is Nothing Then
                    Exit Do
                Else
                    returnStr &= Incoming & vbCrLf
                End If
            Loop
        Catch ex As TimeoutException
            returnStr = "Error: Serial Port read timed out."
        Finally
            If com1 IsNot Nothing Then com1.Close()
        End Try

        Return returnStr
        MsgBox(returnStr)
      End Function