Why can't I build the iPhone app in xcode?

Hey, This maybe be a si开发者_高级运维mple question but I'm not able to build my app in xcode. The Build and run button along with the breakpoints and Tasks buttons are not clickable. Why is this so?

Thanks

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You already built and ran the app, and the debugger is still attached. Go to Run | Stop.

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Try giving Shift-Cmd-R ( this should definitely bring up your output window if the app is running and by any means the output window is not turning up previously )