How to display 2 lines of text for subtitle of MKAnnotation and change the image for the button on the right?

Question

I am looking at Apple's MapCallouts example for map annotations and callouts (==bubbles that appear when you click on a pin). Every annotation there has coordinates, title and subtitle. I would like to display subtitle in 2 lines, i tried with:

- (NSString *)subtitle
{
return @"Founded: June 29, 1776\nSecond line text";
}

but the text "Second line text" stays in one line and makes bubble wider.I get this:

I would also like to change image of the button to one of my own's, the code that sets the button is currently like this:

UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];

Any ideas?

EDIT: I tried 7KV7's advice. Button change is successful, but i still cant get subtitles in 2 lines. My code:

MKPinAnnotationView* customPinView = [[[MKPinAnnotationView alloc]
                                        initWithAnnotation:annotation reuseIdentifier:BridgeAnnotationIdentifier] autorelease];
        customPinView.pinColor = MKPinAnnotationColorPurple;
        customPinView.animatesDrop = YES;


        // Button
        UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
        button.frame = CGRectMake(0, 0, 23, 23);
        button.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
        button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

        //UIEdgeInsets titleInsets = UIEdgeInsetsMake(7.0, -20.0, 7.0, 7.0);
        //button.titleEdgeInsets = titleInsets;

        [button setImage:[UIImage imageNamed:@"ic_phone_default.png"] forState:UIControlStateNormal];
        //[button setImage:[UIImage imageNamed:@"ic_phone_selected.png"] forState:UIControlStateSelected];
        [button setImage:[UIImage imageNamed:@"ic_phone_selected.png"] forState:UIControlStateHighlighted];
        [button addTarget:self action:@selector(showDetails:) forControlEvents:UIControlEventTouchUpInside];

        customPinView.rightCalloutAccessoryView = button;

        //two labels
        UIView *leftCAV = [[UIView alloc] initWithFrame:CGRectMake(0,0,50,50)];
        //[leftCAV addSubview : button];
        UILabel *l1=[[UILabel alloc] init];
        l1.frame=CGRectMake(0, 15, 50, 50);
        l1.text=@"First line of subtitle"; 
        l1.font=[UIFont fontWithName:@"Arial Rounded MT Bold" size:(10.0)];

        UILabel *l2=[[UILabel alloc] init];
        l2.frame=CGRectMake(0, 30, 50, 50);
        l2.text=@"Second line of subtitle";
        l2.font=[UIFont fontWithName:@"Arial Rounded MT Bold" size:(10.0)];
        [leftCAV addSubview : l1];
        [leftCAV addSubview : l2];
        customPinView.leftCalloutAccessoryView = leftCAV;
        //customPinView.
        customPinView.canShowCallout = YES;

        return customPinView;

I get this:

Answer 1

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{   
    MKAnnotationView *annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"loc"];

    // Button
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 23, 23);
button.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

[button setImage:[UIImage imageNamed:yourImageName] forState:UIControlStateNormal];
[advertButton addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchUpInside];

annView.rightCalloutAccessoryView = button;


    // Image and two labels
    UIView *leftCAV = [[UIView alloc] initWithFrame:CGRectMake(0,0,23,23)];
    [leftCAV addSubview : yourImageView];
    [leftCAV addSubview : yourFirstLabel];
    [leftCAV addSubview : yourSecondLabel];
    annotationView.leftCalloutAccessoryView = leftCAV;

    annotationView.canShowCallout = YES;

    return pin;
}

UPDATE

The default style for annotations only supports the title and subtitle. Neither title nor subtitle can include line breaks. You cannot do this without subclassing.

To use a custom view review Apple's sample code:

http://developer.apple.com/library/ios/#samplecode/WeatherMap/Introduction/Intro.html

I also think there is a problem in your code

UILabel *l1=[[UILabel alloc] init];
l1.frame=CGRectMake(0, 15, 50, 50);
l1.text=@"First line of subtitle"; 
l1.font=[UIFont fontWithName:@"Arial Rounded MT Bold" size:(10.0)];

UILabel *l2=[[UILabel alloc] init];
l2.frame=CGRectMake(0, 30, 50, 50);
l2.text=@"Second line of subtitle";
l2.font=[UIFont fontWithName:@"Arial Rounded MT Bold" size:(10.0)];
[leftCAV addSubview : l1];
[leftCAV addSubview : l2];

l1 has a frame (0, 15, 50, 50) and l2 has (0, 30, 50, 50). Wont these two overlap? I mean l1 will start from y=15 and its height is 50. so when l2 starts from 30 it may overlap.. Can you pls check by changing the frames