iAd banner integration with cocos2d 1x banner does not show - ios

Question

I am trying to integrate iAd with my existing Cocosd2d 1.x project. I picked up the codes from this site. I put this in my main menu class. it compiles and link fine but the banner is not showing. The NSlog shows that bannerViewDidLoadAd is called. What am I missing here? Your help is highly appreciated. The code is given below.
//iAd begin
-(void)onEnter
{
[super onEnter];
NSLog(#"onEnter called");
adView = [[ADBannerView alloc]initWithFrame:CGRectZero];
adView.delegate = self;
adView.requiredContentSizeIdentifiers = [NSSet setWithObjects:ADBannerContentSizeIdentifier320x50, ADBannerContentSizeIdentifier480x32, nil];
adView.currentContentSizeIdentifier = ADBannerContentSizeIdentifier480x32;
CGSize widowSize = [[CCDirector sharedDirector] winSize];
adView.center = CGPointMake(adView.frame.size.width/2, widowSize.height/2+145);
adView.hidden = YES;
}
-(void)onExit
{
NSLog(#"onExit called");
adView.delegate = nil;
[adView removeFromSuperview];
[adView release];
adView = nil;
[super onExit];
}
-(void)bannerViewDidLoadAd:(ADBannerView *)banner
{
NSLog(#"bannerViewDidLoadAd called");
adView.hidden = NO;
}
-(void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error
{
NSLog(#"banner didFailToReceiveAdWithError called");
adView.hidden = YES;
}
-(void)bannerViewActionDidFinish:(ADBannerView *)banner
{
NSLog(#"bannViewActiondidFinishe called");
[[UIApplication sharedApplication] setStatusBarOrientation:(UIInterfaceOrientation)[[CCDirector sharedDirector]deviceOrientation]];
}
-(BOOL)bannerViewActionShouldBegin:(ADBannerView *)banner willLeaveApplication:(BOOL)willLeave
{
NSLog(#"bannerviewActionShouldBegin called");
return YES;
}
//end iAd

Answer 1

You add this code to your onEnter method,
[[[CCDirector sharedDirector]view] addSubview:adView];

Answer 2

Regarding your specific question, I think #Liya is on the right track: you need to add the AdBannerView object to the view hierarchy; now, you're just creating the object but not using it.
Not sure if it will help, but I wrote recently a tutorial on integrating iAds with Cocos2d-x. The language is different (C++ instead of Objective-C), but the organization of code and some software engineering tips might be helpful if you want to integrate iAds with the scenes and layers of your game in Cocos2d: http://becomingindiedev.blogspot.com.es/2015/02/integrating-iad-in-cocos2d-x-v3x.html