C# windows chat application

Question

private void MessageCallBack(IAsyncResult aResult)

{

int size = sck.EndReceiveFrom(aResult, ref epRemote);

if (size > 0)

{

byte[] recevivedData = new byte[1464];

recevivedData = (byte[])aResult.AsyncState;

ASCIIEncoding eEncoding = new ASCIIEncoding();

string recevieMessage = eEncoding.GetString(recevivedData);

listBox1.Items.Add("Friend:" + recevieMessage); //In this Line Im getting error Cross-thread operaation not valid: Control 'listBox1' accessed from a                                                                                     thread other than the thread it was created on

                                                                                   i can send msg to my friend but while receiving the message im getting the error as i mentioned above                                                                                     so pls help me..

}

byte[] buffer = new byte[1500];

sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);

}