SocketException driving me crazy:(

Unhandled Exception: System.Net.Sockets.SocketException: An attempt was made to
access a socket in a way forbidden by its access permissions
at System.Net.Sockets.Socket.Listen(Int32 backlog)
at MainClass.Main()

This is the code..

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

class MainClass
{
public static void Main()
{

IPEndPoint ip = new IPEndPoint(IPAddress.Any,9999);
Socket socket = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);

socket.Bind(ip);
socket.Listen(10);
Console.WriteLine("Waiting for a client...");
Socket client = socket.Accept();
IPEndPoint clientep =(IPEndPoint)client.RemoteEndPoint;
Console.WriteLine("Connected with {0} at port {1}",clientep.Address, clientep.Port);

string welcome = "Welcome";
byte[] data = new byte[1024];
data = Encoding.ASCII.GetBytes(welcome);
client.Send(data, data.Length,SocketFlags.None);

Console.WriteLine("Disconnected from {0}",clientep.Address);
client.Close();
socket.Close();
}
}

[1279 byte] By [SDan] at [2008-1-7]