- (IBAction)addLoginItem:(id)sender
{
    NSDictionary* errorDict;
    NSAppleEventDescriptor* returnDescriptor = NULL;

    NSAppleScript* scriptObject = [[NSAppleScript alloc] initWithSource:
                @"\
                set app_path to path to me\n\
                tell application \"System Events\"\n\
                if \"AddLoginItem\" is not in (name of every login item) then\n\
                make login item at end with properties {hidden:false, path:app_path}\n\
                end if\n\
                end tell"];

    returnDescriptor = [scriptObject executeAndReturnError: &errorDict];
    [scriptObject release];

    if (returnDescriptor != NULL)
    {
        // successful execution
        if (kAENullEvent != [returnDescriptor descriptorType])
        {
            // script returned an AppleScript result
            if (cAEList == [returnDescriptor descriptorType])
            {
                 // result is a list of other descriptors
            }
            else
            {
                // coerce the result to the appropriate ObjC type
            }
        } 
    }
    else
    {
        // no script result, handle error here
    }
}

- (IBAction)sendFinderEvent:(id)sender
{
    // load the script from a resource by fetching its URL from within our bundle
    NSString* path = [[NSBundle mainBundle] pathForResource:@"SendFinderMessage" ofType:@"scpt"];
    if (path != nil)
    {
        NSURL* url = [NSURL fileURLWithPath:path];
        if (url != nil)
        {
            NSDictionary* errors = [NSDictionary dictionary];
            NSAppleScript* appleScript =
                    [[NSAppleScript alloc] initWithContentsOfURL:url error:&errors];
            if (appleScript != nil)
            {
                // create the first parameter
                NSAppleEventDescriptor* firstParameter =
                        [NSAppleEventDescriptor descriptorWithString:@"Message from my app."];

                // create and populate the list of parameters (in our case just one)
                NSAppleEventDescriptor* parameters = [NSAppleEventDescriptor listDescriptor];
                [parameters insertDescriptor:firstParameter atIndex:1];

                // create the AppleEvent target
                ProcessSerialNumber psn = {0, kCurrentProcess};
                NSAppleEventDescriptor* target =
                [NSAppleEventDescriptor
                        descriptorWithDescriptorType:typeProcessSerialNumber
                        bytes:&psn
                        length:sizeof(ProcessSerialNumber)];

                // create an NSAppleEventDescriptor with the script's method name to call,
                // this is used for the script statement: "on show_message(user_message)"
                // Note that the routine name must be in lower case.
                NSAppleEventDescriptor* handler =
                        [NSAppleEventDescriptor descriptorWithString:
                        [@"show_message" lowercaseString]];

                // create the event for an AppleScript subroutine,
                // set the method name and the list of parameters
                NSAppleEventDescriptor* event =
                        [NSAppleEventDescriptor appleEventWithEventClass:kASAppleScriptSuite
                                eventID:kASSubroutineEvent
                                targetDescriptor:target
                                returnID:kAutoGenerateReturnID
                transactionID:kAnyTransactionID];
                [event setParamDescriptor:handler forKeyword:keyASSubroutineName];
                [event setParamDescriptor:parameters forKeyword:keyDirectObject];

                // call the event in AppleScript
                if (![appleScript executeAppleEvent:event error:&errors]); 
                {
                    // report any errors from 'errors'
                }

                [appleScript release];
            }
            else
            {
                // report any errors from 'errors'
            }
        }
    }
}

on show_message(user_message)     tell application "Finder"         display dialog user_message     end tell end show_message