Code for a TCP messenger

Option Explicit On
Imports System.IO
Imports System.Net.Sockets
Imports System.Net

Public Class Form1
    Dim Client As TcpClient
    Dim Listener As New TcpListener(8000)
    Dim Client2 As TcpClient
    Private Sub _FormClosing() Handles Me.FormClosing
        Listener.Stop()
    End Sub
    Private Sub _Load() Handles MyBase.Load
        Timer2.Start()
        Listener.Start()
    End Sub
    Private Sub _Tick() Handles Timer1.Tick
        txtNick.Hide()
        Dim Message As String
        Dim nStart As Integer
        Dim nLast As Integer

        If Listener.Pending = True Then
            Message = ""
            Client = Listener.AcceptTcpClient()
            Dim Reader As New StreamReader(Client.GetStream())

            While Reader.Peek > -1
                Message &= Convert.ToChar(Reader.Read()).ToString
            End While

            If Message.Contains("</>") Then
                nStart = InStr(Message, "</>") + 4
                nLast = InStr(Message, "<\>")
                Message = Mid(Message, nStart, nLast - nStart)
            End If

            RichTextBox1.AppendText(Message & vbNewLine)
        End If
    End Sub


    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs)


    End Sub

    Private Sub Button3_Click(sender As System.Object, e As System.EventArgs)
        Me.ComboBox1.Items.AddRange(Dns.GetHostAddresses(GetComputerName))
    End Sub

    Private Function GetComputerName() As String
        Return Dns.GetHostName
    End Function

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Timer1.Start()

        Dim r As Rectangle
        If Parent IsNot Nothing Then
            r = Parent.RectangleToScreen(Parent.ClientRectangle)
        Else
            r = Screen.FromPoint(Me.Location).WorkingArea
        End If

        Dim x = r.Left + (r.Width - Me.Width) \ 2
        Dim y = r.Top + (r.Height - Me.Height) \ 2
        Me.Location = New Point(x, y)


        Me.ComboBox1.Items.AddRange(Dns.GetHostAddresses(GetComputerName))
        Label8.Hide()
        Dim myIPaddress As String
        Dim tmpHostName As String = System.Net.Dns.GetHostName()
        myIPaddress = System.Net.Dns.GetHostByName(tmpHostName).AddressList(0).ToString()
        txtNick.Text = myIPaddress
    End Sub

    Private Sub Button2_Click_1(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        Application.Exit()
    End Sub

    Private Sub btnClick(sender As System.Object, e As System.EventArgs)

    End Sub

    Private Sub PictureBox2_Click(sender As System.Object, e As System.EventArgs) Handles PictureBox2.Click
        Dim Person As String
        Person = ComboBox1.Text
        Try
            Client = New TcpClient(Person, 8000)
            Dim Writer As New StreamWriter(Client.GetStream())
            Writer.Write("</> " & TextBox1.Text & " -From " & txtNickname.Text & " (" & txtNick.Text & ")" & " at " & Label8.Text & " <\>")
            Writer.Flush()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        If ComboBox1.Text = Nothing Then
            MsgBox("Please Enter an IP To Recieve Your Message", MsgBoxStyle.Critical)
        End If
        Me.Text = "IPv4 Messanger (Messaging: " & ComboBox1.Text & " as " & txtNick.Text & ")"
        ListBox1.Items.Add(ComboBox1.Text)
    End Sub

    Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged

    End Sub
    Private Sub TextBox1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
        If e.KeyCode = Keys.Enter Then
            Dim Person As String
            Person = ComboBox1.Text
            Try
                Client = New TcpClient(Person, 8000)
                Dim Writer As New StreamWriter(Client.GetStream())
                Writer.Write("</> " & TextBox1.Text & " -From " & txtNickname.Text & " (" & txtNick.Text & ")" & " at " & Label8.Text & " <\>")
                Writer.Flush()
            Catch ex As Exception
                MsgBox(ex.Message)
            End Try
            ListBox1.Items.Add(ComboBox1.Text)
        End If
        Me.Text = "IPv4 Messanger (Messaging: " & ComboBox1.Text & " as " & txtNick.Text & ")"
    End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        TextBox1.Clear()
    End Sub

    Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
        Label8.Text = Format(Now, "hh:mm tt")
    End Sub

    Private Sub ExitToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles ExitToolStripMenuItem.Click
        Application.Exit()
    End Sub

    Private Sub Button3_Click_1(sender As System.Object, e As System.EventArgs) Handles Button3.Click
        ListBox1.Items.Clear()
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged

    End Sub

    Private Sub txtNick_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtNick.TextChanged

    End Sub

    Private Sub Label9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label9.Click

    End Sub

    Private Sub InfoToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles InfoToolStripMenuItem.Click
        MsgBox("IPv4 Messanger uses a system of networking called TCP to send messages from one IPv4 address to another as long as they are on the same WiFi", MsgBoxStyle.Information)
    End Sub

    Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
        RichTextBox1.Clear()
    End Sub

    Private Sub RedToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles RedToolStripMenuItem.Click
        RichTextBox1.ForeColor = Color.Red
        RichTextBox1.BackColor = Color.White
        TextBox1.BackColor = Color.White
        TextBox1.ForeColor = Color.Black
    End Sub

    Private Sub BlackToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles BlackToolStripMenuItem.Click
        RichTextBox1.ForeColor = Color.Black
        RichTextBox1.BackColor = Color.White
        TextBox1.BackColor = Color.White
        TextBox1.ForeColor = Color.Black
    End Sub

    Private Sub PinkToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles PinkToolStripMenuItem.Click
        RichTextBox1.ForeColor = Color.Violet
        RichTextBox1.BackColor = Color.White
        TextBox1.BackColor = Color.White
        TextBox1.ForeColor = Color.Black
    End Sub

    Private Sub BlueToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles BlueToolStripMenuItem.Click
        RichTextBox1.ForeColor = Color.Blue
        RichTextBox1.BackColor = Color.White
        TextBox1.BackColor = Color.White
        TextBox1.ForeColor = Color.Black
    End Sub

    Private Sub LimeToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles LimeToolStripMenuItem.Click
        RichTextBox1.ForeColor = Color.Green
        TextBox1.BackColor = Color.White
        TextBox1.ForeColor = Color.Black
        RichTextBox1.BackColor = Color.White
    End Sub

    Private Sub H4X0RToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles H4X0RToolStripMenuItem.Click
        RichTextBox1.ForeColor = Color.Lime
        RichTextBox1.BackColor = Color.Black
        TextBox1.BackColor = Color.Black
        TextBox1.ForeColor = Color.Lime
    End Sub

    Private Sub Timer2_Tick(sender As System.Object, e As System.EventArgs) Handles Timer2.Tick

    End Sub

    Private Sub Label8_Click(sender As System.Object, e As System.EventArgs) Handles Label8.Click

    End Sub
End Class