Problem with implementing iAd into iPhone application

okay so i have completely followed multiple tutorials step by step including this one iAd Tutorial

and using apples official sample code.. everytime i get the err开发者_C百科ors: "_CGRectOffset" Referenced from: and _CGRectZero Referenced from: any help guys?

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CGRectZero and CGRectOffset are in the CoreGraphics framework.

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You have to add the CoreGraphics framework to your project in the linker settings.