vb.net weighbridge scale com port reading live

Question

I have to read my weighbridge scale value to system ,I have created vb.net file for this and getting reading .but I need live reading and if com port is not detected just get message popup instead of error .Thanks advance for your advice.

Imports System. Text
Imports System.IO.Ports
Imports System.Windows.Forms
Imports System. Threading
Imports System. Timers
Imports System.IO
Imports System. Text. RegularExpressions
Imports System. Xml
Imports System. Data

Public Class Form2


  
    Private Sub BtnConnect_Click(sender As Object, e As Eventers) Handles BtnConnect_Click
        txtData.Text = ""
        serialport1 = New Serial Port

        serialport1.PortName = "COM6"
        serialport1.Open()
        serialport1.BaudRate = 9600
        serialport1.Parity = Parity. None
        serialport1.DataBits = 8
        serialport1.StopBits = StopBits.One
        serialport1.DtrEnable = True
        serialport1.RtsEnable = True
        serialport1.Handshake = IO.Ports.Handshake.None
        serialport1.ReceivedBytesThreshold = 1
        txtData.Text = Extract Numbers(serialport1.ReadExisting())
            serialport1.Close()

        If serialport1.IsOpen = False Then
            MsgBox("not")
            Exit Sub
        End If
        
    End Sub