shut down the computer

Question

hi all... i wanna to develop an application to shut down the computer using C#.... i did it and call ExitWondowsEx API......it works fine in windows 98.... but in windows xp i doesn't work....becauseof the priviliges..... does any one know the code in C# to handle the priviliges??....... or does any one know how to use Sytem.management to shut down the computer??? thx in advance