Visual basic ICMP Pinger? - vb.net

Question

I am building an ICMP Pinger in visual basic.
I would like to be able to determine the destination address, time out, size of packets, and how many packets to send.
I only have a small amount of programming knowledge, does anybody have any suggestions? Or a more efficient way to run the program?
Here is what i have that is working so far.
Option Explicit On
Option Infer Off
Imports System.Net.NetworkInformation
Imports System.ComponentModel
Public Class Form1
Private WithEvents bwPing As New BackgroundWorker
Private pingTarget As String
Private pingsize As Integer
Private numOfpings As Integer
Dim timeout As Integer
Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
' start pinger
bwPing.WorkerReportsProgress = True
bwPing.WorkerSupportsCancellation = True
pingTarget = TextBox2.Text
timeout = ComboBox4.Text
If Not bwPing.IsBusy Then bwPing.RunWorkerAsync()
If ComboBox3.Text & ComboBox1.Text = "" Then
bwPing.CancelAsync()
ListBox1.Items.Add("*****!!!!!***** INVALID ENTRY *****!!!!!*****")
MsgBox(" By failing to prepare, you are preparing to fail. ", MsgBoxStyle.Exclamation)
ElseIf ComboBox3.Text = "" Then
bwPing.CancelAsync()
ListBox1.Items.Add("*****!!!!!***** INVALID ENTRY *****!!!!!*****")
MsgBox(" How many troops are you sending in? ", MsgBoxStyle.Exclamation)
ElseIf ComboBox1.Text = "" Then
bwPing.CancelAsync()
ListBox1.Items.Add("*****!!!!!***** INVALID ENTRY *****!!!!!*****")
MsgBox(" How strong are your soldiers? ", MsgBoxStyle.Exclamation)
Else : numOfpings = CInt(ComboBox3.Text)
pingsize = CInt(ComboBox1.Text)
End If
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
' cancel pinger
bwPing.CancelAsync()
End Sub
Private Sub Button3_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button3.Click
' clear
ListBox1.Items.Clear()
ComboBox1.Text = ""
ComboBox3.Text = ""
ProgressBar1.Value = 0
End Sub
Private Sub bwPing_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs) Handles bwPing.DoWork
' ping worker
Dim worker As BackgroundWorker = CType(sender, BackgroundWorker)
Dim packet(pingsize) As Byte
For i As Integer = 0 To numOfpings - 1
bwPing.ReportProgress(i + 1)
Dim ping As New Ping
Dim reply As PingReply = ping.Send(pingTarget, timeout)
If ComboBox3.Text & ComboBox1.Text = "" Then
bwPing.CancelAsync()
Else
ListBox1.Items.Add("You hit " & pingTarget & " in " & reply.RoundtripTime.ToString() & " ms with " & pingsize & " bytes.")
System.Threading.Thread.Sleep(500)
End If
If worker.CancellationPending Then Exit For
Next
End Sub
Private Sub bwPing_ProgressChanged(ByVal sender As Object, ByVal e As ProgressChangedEventArgs) Handles bwPing.ProgressChanged
' update results
Me.ProgressBar1.Value = e.ProgressPercentage
ProgressBar1.Minimum = 0
ProgressBar1.Maximum = numOfpings
End Sub
Private Sub bwPing_RunWorkerCompleted(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs) Handles bwPing.RunWorkerCompleted
' finished
Me.ListBox1.Items.Add("*!* The battle is over, but not the war *!*")
bwPing.CancelAsync()
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Control.CheckForIllegalCrossThreadCalls = False
End Sub
End Class