Question

#pragma mark - iAd method.


/*Starts:iAd*/

-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{

    Class cls = NSClassFromString(@"ADBannerView");
    if(cls!=nil)
    {
        [self layoutForCurrentOrientation:YES];
    }   

}

-(void)createADBannerView
{

    NSString *contentSize = UIInterfaceOrientationIsPortrait(self.interfaceOrientation) ? ADBannerContentSizeIdentifierPortrait : ADBannerContentSizeIdentifierPortrait;

    CGRect frame;
    frame.size = [ADBannerView sizeFromBannerContentSizeIdentifier:contentSize];
    frame.origin = CGPointMake(0.0, CGRectGetMaxY(self.view.bounds));


    // Now to create and configure the banner view
    ADBannerView *bannerView = [[ADBannerView alloc] initWithFrame:frame];
    // Set the delegate to self, so that we are notified of ad responses.
    bannerView.delegate = self;
    // Set the autoresizing mask so that the banner is pinned to the bottom
    bannerView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleTopMargin;
    bannerView.requiredContentSizeIdentifiers = [NSSet setWithObjects:ADBannerContentSizeIdentifierPortrait, ADBannerContentSizeIdentifierPortrait, nil];

    // At this point the ad banner is now be visible and looking for an ad.
    [self.view addSubview:bannerView];
    self.banner = bannerView;
    [bannerView release];
}


-(void)layoutForCurrentOrientation:(BOOL)animated
{

    CGFloat animationDuration = animated ? 0.2 : 0.0;
    // by default content consumes the entire view area
    CGRect contentFrame = self.view.bounds;
    CGPoint bannerOrigin = CGPointMake(CGRectGetMinX(contentFrame), CGRectGetMaxY(contentFrame));
    CGFloat bannerHeight = 0.0;

    banner.currentContentSizeIdentifier = ADBannerContentSizeIdentifierPortrait;
    bannerHeight = 55.0;

    if(banner.bannerLoaded)
    {
        contentFrame.size.height -= bannerHeight;
        bannerOrigin.y -= bannerHeight;
    }
    else
    {
        bannerOrigin.y += bannerHeight;
    }

    // And finally animate the changes, running layout for the content view if required.

    NSLog(@"[UIApplication sharedApplication].statusBarOrientation = %d",[UIApplication sharedApplication].statusBarOrientation);



    [UIView animateWithDuration:animationDuration
                     animations:^{
                         contentView.frame = contentFrame;
                         [contentView layoutIfNeeded];

                         banner.frame = CGRectMake(0,361, banner.frame.size.width, banner.frame.size.height);   
                     }];
}


/*Ends:iAd*/

/*Starts:Added By:CP.Date:26-Dec-2010.
 AdMob methods*/

#pragma mark - AdMobDelegate methods

-(NSString *) publisherIdForAd:(AdMobView *)adView

{

    return @"a14f91029b8c719"; // this should be prefilled; if not, get it from www.admob.com
}

-(UIViewController *) currentViewControllerForAd:(AdMobView *)adView
{

    return self;
}

-(UIColor *)adBackgroundColorForAd:(AdMobView *)adView 
{

    return [UIColor colorWithRed:0 green:0 blue:0 alpha:1]; // this should be prefilled; if not, provide a UIColor
}

-(UIColor *)primaryTextColorForAd:(AdMobView *)adView 
{

    return [UIColor colorWithRed:1 green:1 blue:1 alpha:1]; // this should be prefilled; if not, provide a UIColor
}

-(UIColor *)secondaryTextColorForAd:(AdMobView *)adView 
{

    return [UIColor colorWithRed:1 green:1 blue:1 alpha:1]; // this should be prefilled; if not, provide a UIColor
}

-(void) didReceiveAd:(AdMobView *)adView
{

    adMobAd.frame = CGRectMake(0,361,320,55);

    //adMobAd = [AdMobView requestAdOfSize:ADMOB_SIZE_748x110 withDelegate:self];
    [self.view addSubview:adMobAd];
}

// Sent when an ad request failed to load an ad

-(void)didFailToReceiveAd:(AdMobView *)adView 
{

    Class cls = NSClassFromString(@"ADBannerView");
    if(cls!=nil)
    {
        if(banner == nil)
        {
            [self createADBannerView];
        }
        [self layoutForCurrentOrientation:NO];
    }   

    [adMobAd removeFromSuperview];  // Not necessary since never added to a view, but doesn't hurt and is good practice
    [adMobAd release];
    adMobAd = nil;
    // we could start a new ad request here, but in the interests of the user's battery life, let's not
}

/*Ends:Added By:CP.Date:26-Dec-2010.
 AdMob methods*/

Answer 1

first of all be clear about iad or admob , that are two different plateform for displaing adv in your app.
i think you are try to integrate admob adv. you need to following steps for it.

http://www.edumobile.org/iphone/iphone-programming-tutorials/how-to-admob-integrate-in-your-application-in-iphone/