/// <summary>
/// Send a text message to the remote client.
/// </summary>
/// <param name="message"></param>
public void SendTextMessage(String message, String clientName)
{
checkReceiver(clientName);
var encryptionkey = clientPublicEncryptionkeys[clientName];
TextMessageRequest request = new TextMessageRequest();
request.ReceiverClient = clientName;
request.Message = UtilityFunction.EncryptString(message, encryptionkey.FirstX, encryptionkey.U, encryptionkey.SelectChoas);
SendMessage(request);
}