Error with 1 file for multiple iAds

im creating an app with ads but i have the problem that i have mutiple ads in multiple view and i just want all of that in one file this is my error and my code

iAd.swift :

 import iAd
 import Foundation

class iAd: ADBannerView, ADBannerViewDelegate {
    func bannerViewWillLoadAd(banner: ADBannerView!) {
    }
    func bannerViewDidLoadAd(banner: ADBannerView!) {
    }
    func bannerViewActionDidFinish(banner: ADBannerView!) {
    }
    func bannerViewActionShouldBegin(banner: ADBannerView!,     willLeaveApplication willLeave: Bool) -> Bool {
        return true
    }
    func bannerView(banner: ADBannerView!, didFailToReceiveAdWithError       error: NSError!) {
        println(error)
    }
}

and view controller.swift :

import UIKit
import iAd

class ViewController: UIViewController {

    @IBOutlet var adBannerView: iAd!
    override func viewDidLoad() {
        super.viewDidLoad()
        self.canDisplayBannerAds = true
        self.adBannerView.delegate = iAd() as ADBannerViewDelegate
        self.adBannerView.hidden = false
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}