manual install of system service

[Pawel Janik]

Hello.

I want to install new system service, but not using instalutil, but manualy,
from my application. There is my code, that should do this:

Installer installer = new Installer();
ServiceProcessInstaller spi = new ServiceProcessInstaller();
spi.Account = ServiceAccount.User;

ServiceInstaller si = new ServiceInstaller();
si.ServiceName = "TJ";
si.DisplayName = "Test Janos";

si.StartType = ServiceStartMode.Manual;
si.Committed += new InstallEventHandler(CommittedEventHandler);

installer.Installers.Add(si);
installer.Installers.Add(spi);
ListDictionary state = new ListDictionary();

installer.Install(state);

but it throws:

Unhandled Exception: System.NullReferenceException: Object reference not set
to
an instance of an object.
at System.ServiceProcess.ServiceInstaller.Install(IDi ctionary stateSaver)
at System.Configuration.Install.Installer.Install(IDi ctionary stateSaver)
at test.MainClass.Main(String[] args) in Main.cs:line 34

Have anybody any idea, what can i do wrong?

regards,
Pawel Janik