求助一下,2000和XP下关机的API应该怎么写.怎么用.我的写了不行.

获取操作系统的权限：
procedure Tfrmmain.FormCreate(Sender: TObject);

var

hToken : THandle;

Tkp : TTokenPrivileges;

Zero:DWORD;

begin

OpenProcessToken(GetCurrentProcess(),TOKEN_ADJUST_PRIVILEGES or

TOKEN_QUERY,hToken);

LookupPrivilegeValue(nil,'SeShutdownPrivilege',tkp.Privileges[0].Luid);

Tkp.PrivilegeCount :=1;

Tkp.Privileges[0].Attributes := SE_PRIVILEGE_ENABLED;

AdjustTokenPrivileges(hToken,False,Tkp,SizeOf(TTokenPrivileges),nil,Zero);
end;

注销：Exitwindowsex(Ewx_logoff,0);
重启：Exitwindowsex（ewx_reboot,0）;
关闭计算机：Exitwindowsex(ewx_shutdown or poweroff,0);