trying to stretch width

#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIScrollView *scrollViewForAccordian;

@end

@implementation ViewController

@synthesize scrollViewForAccordian;

- (void)viewDidLoad {
    [super viewDidLoad];
    [self makeCell];
}

- (void)makeCell {
    //Making the Cell
    UIView *viewForOutertable = [[UIView alloc]initWithFrame:CGRectMake(0, 0, ([[ UIScreen mainScreen ] bounds].size.width), 44)];
    viewForOutertable.translatesAutoresizingMaskIntoConstraints = NO;
    NSDictionary *viewsDictionary = @{@"Cell":viewForOutertable};

    NSArray *constraint_V = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[myCell]-0-|"
                                                                    options:0
                                                                    metrics:nil
                                                                      views:viewsDictionary];
    [viewForOutertable addConstraint:constraint_V];


    //Setting the buttons
    UIButton *buttonToEnlarge = [[UIButton alloc]initWithFrame:CGRectMake(0, 0, ([[ UIScreen mainScreen ] bounds].size.width) , 44)];
    [buttonToEnlarge setImage:[UIImage imageNamed:@"ltgrey.jpg"]
                     forState:UIControlStateNormal];

    [buttonToEnlarge setImage:[UIImage imageNamed:@"grey.jpg"]
                     forState:UIControlStateSelected];
    [buttonToEnlarge addTarget:self
                        action:@selector(expandButtonTapped:)
              forControlEvents: UIControlEventTouchUpInside];

    [viewForOutertable addSubview:buttonToEnlarge];

    [scrollViewForAccordian addSubview:viewForOutertable];

}

-(void)expandButtonTapped:(UIButton *)sender {
    NSLog(@"Button Clicked");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end