Abort Windwos Shutdown

Can any body tell me how to abort the system shutdown based on the user action weather he or she wants to continue shutdown or cancel the windows shutdown.

I also require help on AbortSystemShutdown API - the parameter of this API is lpMachineName. What value is requird to pass to it.

------------------
Love , Neerad

lpMachineName

Points to the null-terminated string that specifies the network name of the computer where the shutdown is to be stopped. If lpMachineName is NULL or points to an empty string, the function stops the shutdown on the local computer.

Thanks Babuger,
But i tried to pass null to the API AbortSystemShutDown it didn't work. What i want is How to terminate the shutdown on a local machine.

Any way Thanx a lot