如何使用TRegistry对注册表读和写!!!!!!!!!

var
  Reg: TRegistry;
begin
  Reg := TRegistry.Create;
  try
    Reg.RootKey := HKEY_CURRENT_USER;
    if Reg.OpenKey('\Software\Microsoft\Windows\CurrentVersion\RunOnce', True) then
   begin
      Reg.WriteString('MyApp','"' + ParamStr(0) + '"');
      Reg.CloseKey;
    end;
  finally
    Reg.Free;
    inherited;
  end;end;
//from delphi help