Hey

I have checked my code multiple times and downloaded the code given for the book

but when i try to run nothing happens i get blank screens in the simulator
and when i try to build i get this error

no sdk with the name or path ' iphone 4.0' or something similar, im on chpter 3 and until now i have managed to get alert views etc.. to load, its not a typo either.

neither webView or page control and image view work, im starting to wonder if its the code in the book, or something simple which im missing.

Check the following:
In the Xcode, on the Project window watch the leftmost and upper clicking window. It should show Simulator-4.2, Debug, Project Name. If it show Missing SDK is because when you open the Project from the book downloaded file it does not identify the SDK Version.
You should go to Xcode menu bar and select Project>Edit Project Settings and choose Base SDK to 4.2 if this is the version you are using. Save the changes an make Build and Run. If the problem persists, close Xcode (it ask to save ALL the changes) click OK, open the project again and you should be done.