form do not take any action when tcpListener is start

hi
i create a very simple server-client chat program.
in the server form , i put a textbox to recieve msg from clients and a button to start tcpListener.when i click this button tcpListener is start but the form is freeze.i cant choose any thing in this form.what can i do to fix this problem?

Yoy will have to show some code, as the problem can be anything, and without seeing your code; it is way too difficult to exactly tell you where the problems are.

sure ...
this is the server codes :

Code:

---

Imports System.Text
Imports System.Net
Imports System.Net.Sockets

Public Class Server
    Public ip As IPAddress = GetMyIP()
    Public TCPlistener As TcpListener = New TcpListener(ip, 2500)
    Private Sub Chat()
        Dim Messages(7) As String
        Dim a As New AutoResetEvent(False)
        While CheckBox1.Checked = True
            Try
                TCPlistener.Start()
                ListBox1.Items.Clear()
                ListBox1.Items.Add("The server is ruuning as port :" & Str(2500))
                Dim F As New Form
                Controls.Add(F)
                F.Size = New Size(100, 100)
                F.Refresh()

                Dim MyEndpoint As IPEndPoint = CType(TCPlistener.LocalEndpoint, IPEndPoint)
                ListBox1.Items.Add("The local EndPoint address is :" & MyEndpoint.Address.ToString)
                ListBox1.Items.Add("Waiting for connectiom ...")
                Dim sock As Socket = TCPlistener.AcceptSocket
                MyEndpoint = CType(sock.RemoteEndPoint, IPEndPoint)
                ListBox1.Items.Add("Connection accepted from :" & MyEndpoint.Address.ToString)
                Dim ByteData(100) As Byte
                Dim size As Integer = sock.Receive(ByteData)
                ListBox1.Items.Add("Recieved")
                Dim RecieveText As String = Nothing
                For i = 0 To size
                    RecieveText = RecieveText & Convert.ToChar(ByteData(i))
                Next
                Dim AsciiEncod As New ASCIIEncoding
                ListBox1.Items.Add("Sending alert to client !")
                sock.Send(AsciiEncod.GetBytes("The string was recieved by the server !"))
                sock.Close()
                MsgBox(RecieveText)
                TCPlistener.Stop()
            Catch ex As Exception
                MsgBox(ex.Message)
            End Try
        End While
    End Sub
End Class

---

this is the client codes :

Code:

---

Imports System.Net
Imports System.Net.Sockets
Imports System.Threading
Imports System.Text
Imports System.IO

Public Class Form1

    Private Sub btnSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSend.Click
        Try
            txtMessages.Text = Nothing
            Dim TCPclient As New TcpClient
            txtMessages.Text = txtMessages.Text & "Connecting ..." & vbCrLf
            Dim MyIP As IPAddress = GetMyIP()
            Dim SysPort As Int32 = Convert.ToInt16(txtPort.Text)
            TCPclient.Connect(MyIP.ToString, SysPort)
            txtMessages.Text = txtMessages.Text & "Connected" & vbCrLf
            txtMessages.Text = txtMessages.Text & "Enter a text to send ..." & vbCrLf
            txtSendMess.Focus()
            Dim StrMessage As String = txtSendMess.Text
            Dim stm As Stream = TCPclient.GetStream
            Dim AsciiEncod As New ASCIIEncoding
            Dim ByteData() As Byte = AsciiEncod.GetBytes(StrMessage)
            txtMessages.Text = txtMessages.Text & "Sending" & vbCrLf
            stm.Write(ByteData, 0, ByteData.Length)
            Dim ReplyMessage(100) As Byte
            Dim size As Integer = stm.Read(ReplyMessage, 0, 100)
            txtMessages.Text = txtMessages.Text & "This msg is from server :"
            Dim str As String = Nothing
            For i = 0 To size
                str = str & Convert.ToChar(ReplyMessage(i))
            Next
            txtMessages.Text = txtMessages.Text & str & vbCrLf
            TCPclient.Close()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub

---

i searched in google and find something about threading . if it is possible for you show me the solution with code or with correct this code .

Look at working examples for your language choice. http://code.msdn.microsoft.com/

That will explain the problems you are having.