sending and receiving data using networkstream

[hamid_2020]

I wrote a class to connect to a server using tcpclient.
I need to connect to the server and the connection must be open.Then i need to send request to the server again and again.But the problem is that i can communicate with the servet just for one time,the first time i connect to the server,send data and receive response,but when i want to receive data for another time,there won't be any response.some body help me please,whats the problem???
this is the class code i wrote:
----------------------------------------------------------------------

public class TCPAgent
{

TcpClient TCPconn = new TcpClient();
NetworkStream NetWorkStream;
public void Connect(string Server , int port)
{
TCPconn.Connect (Server, port);
NetWorkStream = TCPconn.GetStre am();

}

public string transfer(string SendCommand)
{
byte[] SendCmd = Encoding.ASCII. GetBytes(SendCo mmand);
NetWorkStream.W rite(SendCmd,0, SendCmd.Length) ;
StreamReader objSR = new StreamReader(TC Pconn.GetStream (), Encoding.ASCII) ;
return (objSR.ReadToEn d());
}
public string close
{
set
{
this.NetWorkStr eam.Close();
this.TCPconn.Cl ose();
}


}



}

[Banfa]

OK I am guessing here but I think it might be worth finding out what the server is doing. I think it may be possible that having handled a request the server is then closing the connection so that no more requests work. I think that you have to tell the server, somehow, to keep your connection live until you say otherwise.