//подключение к серверу
void ConnectUser()
{
if (!isConnected)
{
client = new ServiceChatClient(new System.ServiceModel.InstanceContext(this));
PrintUsers();
Id = client.Connect(tblockUserName.Text);
client.SendOnlineUsers(tbMessage.Text, Id);
tblockUserName.Foreground = Brushes.Green;
isConnected = true;
}
}