Application not preventing shutdown on Mac

I am trying to get a Mac OS X application to prevent shutdown/sleep/restart. Here is my main.m from the Xcode project:

// 
//  main.m
//  CurrencyConverter
//
//  

#import <Cocoa/Cocoa.h>

OSErr QuitAppleEventHandler开发者_开发技巧( const AppleEvent *appleEvt, 
                            AppleEvent* reply, UInt32 refcon )
{
    //returning userCanceledErr to cancel logout
    return userCanceledErr;
}

int main(int argc, char *argv[])
{
    OSErr   err;

    //Installing quit event handler
    err = AEInstallEventHandler( kCoreEventClass, 
                                kAEQuitApplication,  NewAEEventHandlerUPP(
                                                                          (AEEventHandlerProcPtr)QuitAppleEventHandler),  
                                0, false );

    if (err != noErr)
        ExitToShell();

    return NSApplicationMain(argc,  (const char **) argv);
}

Somehow when I build and run, I am unable to get the required outcome. It still sleeps, shuts down and etc. I just want to know what I did wrong. I got the code snippet from http://developer.apple.com/library/mac/#technotes/tn2002/tn2062.html under the prevent shutdown etc part. I understand I can use kiosks and all but I am not sure how I can integrate it into my application. Thank you.

Nope!!!

Works fine for me. I think your issue is that the program is not running continually. So when it exits, all system hooks are removed.