I am developing one 2d game using cocos2d framework, in this game i am using admob for advertising, in some classes not in all classes but admob banner is visible in every class and after some time game getting crash also.

I am not getting how admob banner is comes in every class in fact i have not declare in Rootviewcontroller class. can any one suggest me how to integrate Admob in cocos2d game, i want Admob banner in particular classes not in every class, I am using latest google admob sdk, my code is below:

Thanks in advance

`

-(void)AdMob{
NSLog(@"ADMOB");


CGSize winSize = [[CCDirector sharedDirector]winSize];
// Create a view of the standard size at the bottom of the screen.


if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){

    bannerView_ = [[GADBannerView alloc]
                  initWithFrame:CGRectMake(size.width/2-364,
                                           size.height -
                                           GAD_SIZE_728x90.height,
                                           GAD_SIZE_728x90.width,
                                           GAD_SIZE_728x90.height)];

}
else { // It's an iPhone

    bannerView_ = [[GADBannerView alloc]
                  initWithFrame:CGRectMake(size.width/2-160,
                                           size.height -
                                           GAD_SIZE_320x50.height,
                                           GAD_SIZE_320x50.width,
                                           GAD_SIZE_320x50.height)];
}




if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
    bannerView_.adUnitID =@"a15062384653c9e";
}
else {
    bannerView_.adUnitID =@"a15062392a0aa0a";
}

bannerView_.rootViewController = self;
[[[CCDirector sharedDirector]openGLView]addSubview:bannerView_];
[bannerView_ loadRequest:[GADRequest request]];


GADRequest *request = [[GADRequest alloc] init];
request.testing =  [NSArray arrayWithObjects:
                  GAD_SIMULATOR_ID, nil];                              // Simulator

[bannerView_ loadRequest:request];
 }



   //best practice for removing the barnnerView_

-(void)removeSubviews{
 NSArray* subviews = [[CCDirector sharedDirector]openGLView].subviews;
 for (id SUB in subviews){
    [(UIView*)SUB removeFromSuperview];
    [SUB release];
 }
 NSLog(@"remove from view");
  }

    //this makes the refreshTimer count
-(void)targetMethod:(NSTimer *)theTimer{

//INCREASE OF THE TIMER AND SECONDS
elapsedTime++; 
seconds++;

//INCREASE OF THE MINUTOS EACH 60 SECONDS
if (seconds>=60) {
    seconds=0; minutes++;
    [self removeSubviews];
    [self AdMob];
  }
NSLog(@"TIME: %02d:%02d", minutes, seconds);
 }

`