用delphi如何启动一个服务？
用delphi如何启动或者停止一个服务？
我需要的是启动或者停止一个已经存在的服务，
谢谢。

[解决办法]
完整的代码，编译通过，如果还有问题，我就要杀人了。

Delphi(Pascal) code

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, WinSvc, StdCtrls;type  TForm1 = class(TForm)    btnStart: TButton;    procedure btnStartClick(Sender: TObject);  private    { Private declarations }  public    { Public declarations }  end;var  Form1: TForm1;implementation{$R *.dfm}function ServiceStart(const ServiceName: string; const Computer: PChar = nil): Boolean;{  启动服务}var  SCM, SCH: SC_Handle;  P: PChar;begin  Result := False;  SCM := OpenSCManager(nil, nil, SC_MANAGER_ALL_ACCESS);  if SCM <> 0 then  begin    SCH := OpenService(SCM, PChar(ServiceName), SERVICE_ALL_ACCESS);    if SCH <> 0 then    begin      Result := StartService(SCH, 0, P);      CloseServiceHandle(SCH);    end;    CloseServiceHandle(SCM);  end;end;function ServiceStop(const ServiceName: string; const Computer: PChar = nil): Boolean;{  停止服务}var  SCM, SCH: SC_Handle;  ServiceStatus: TServiceStatus;begin  Result := False;  SCM := OpenSCManager(nil, nil, SC_MANAGER_ALL_ACCESS);  if SCM <> 0 then  begin    SCH := OpenService(SCM, PChar(ServiceName), SERVICE_ALL_ACCESS);    if SCH <> 0 then    begin      Result := ControlService(SCH, SERVICE_CONTROL_STOP, ServiceStatus);      CloseServiceHandle(SCH);    end;    CloseServiceHandle(SCM);  end;end;procedure TForm1.btnStartClick(Sender: TObject);begin  ServiceStart('HZ_CommSrv');end;end.