TCP server-multiclients problem

[ancientrd]

From Atheist example and msdn examples i managed to do this small application : i can send and receive text from a client to a server and back.
The problem is i got stuck on : making multiple client connexions , identify the clients and can send msg to a certain client . any help pls ?
i use vb 2009
The server source code :
---------------------------

Imports System.Net.Sockets
Imports System.Net.Sockets
Public Class Form1
    Dim server As TcpListener
    Dim port As Int32 = 13000
    '  Dim localAddr As IPAddress = IPAddress.Parse("127.0.0.1")
    Dim bytes(1024) As Byte
    Dim data As String = Nothing
    Dim stream As NetworkStream
    Dim client As TcpClient
    Dim listenThread As System.Threading.Thread
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            server = New TcpListener(System.Net.IPAddress.Any, port)
            server.Start()
            Label1.Text = "server up"
            listenThread = New System.Threading.Thread(AddressOf doListen)
            listenThread.IsBackground = True
            listenThread.Start()
        Catch ex As Exception
            Label1.Text = "server down"
        End Try

    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim msg As Byte() = System.Text.Encoding.ASCII.GetBytes(TextBox1.Text)
        stream = client.GetStream()
        stream.Write(msg, 0, msg.Length)
        TextBox1.Text = ""
    End Sub
    Private Sub Form1_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed
        server.Stop()
        client.Close()
    End Sub
    Private Delegate Sub StringDelegate(ByVal text As String)
    Private Sub SetConnectionLabelText(ByVal text As String)
        If Me.TextBox2.InvokeRequired Then
            Me.Invoke(New StringDelegate(AddressOf SetConnectionLabelText), text)
        Else
            Me.TextBox2.Text = text
        End If
    End Sub
    Private Sub doListen()
        client = server.AcceptTcpClient()
        Do
            data = Nothing
            stream = client.GetStream()
            Dim iq As Int32
            iq = stream.Read(bytes, 0, bytes.Length)
            data = System.Text.Encoding.ASCII.GetString(bytes, 0, iq)
            SetConnectionLabelText(data)
        Loop
    End Sub
End Class

-------------------------------------------------------------------
the client source code:
-----------------------

Imports System.Net.Sockets
Public Class Form1
    Dim port As Integer = 13000
    Dim server As String
    Dim client As TcpClient
    Dim stream As NetworkStream
    Dim listenThread As System.Threading.Thread
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            server = TextBox3.Text
            client = New TcpClient(server, port)
            stream = client.GetStream()
            Label1.Text = "connected"
            listenThread = New System.Threading.Thread(AddressOf doListen)
            listenThread.IsBackground = True
            listenThread.Start()
        Catch ex As Exception
            Label1.Text = "not connected"
        End Try

    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim data As [Byte]() = System.Text.Encoding.ASCII.GetBytes(TextBox1.Text)
        stream.Write(data, 0, data.Length)
        TextBox1.Text = ""
    End Sub
    Private Sub Form1_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed
        client.Close()
    End Sub
    Private Delegate Sub StringDelegate(ByVal text As String)
    Private Sub SetConnectionLabelText(ByVal text As String)
        If Me.TextBox2.InvokeRequired Then
            Me.Invoke(New StringDelegate(AddressOf SetConnectionLabelText), text)
        Else
            Me.TextBox2.Text = text
        End If
    End Sub
    Private Sub doListen()
        Do
            Dim data As [Byte]() = New [Byte](256) {}
            Dim responseData As [String] = [String].Empty
            Dim bytes As Int32 = stream.Read(data, 0, data.Length)
            responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes)
            SetConnectionLabelText(responseData)
        Loop
    End Sub
End Class