Como saber lo que contiene un TextBox

[jvegae]

Imports System.Net.Sockets
Imports System.Text

Public Class Form1
Dim clientSocket As New System.Net.Sockets.TcpClient()
Dim serverStream As NetworkStream

Sub msg(ByVal mesg As String)
TextBox1.Text = TextBox1.Text + Environment.NewLine + " >> " + mesg
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
msg("Iniciado cliente")
clientSocket.Connect("192.168.10.199", 5100)
Label1.Text = "Programa Cliente Socket - servidor conectado ..."
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim serverStream As NetworkStream = clientSocket.GetStream()
Dim outStream As Byte() = _
System.Text.Encoding.ASCII.GetBytes("Mensaje del cliente$")
serverStream.Write(outStream, 0, outStream.Length)
serverStream.Flush()

Dim inStream(13000) As Byte
serverStream.Read(inStream, 0, CInt(clientSocket.ReceiveBufferSize))
Dim returndata As String = _
System.Text.Encoding.ASCII.GetString(inStream)
msg("Los datos del servidor : " + returndata)
End Sub
End Class