Can not replace the helloworldscene with GameScene in Helloworld sample

Hi,
I successful compile and run the Helloworld sample in emulator. But, when I modify the Helloworld code that remove the helloworldscene and add in
the Gamescene(CCScene *pScene = GameScene::scene():wink: in AppDelegate, the emulator still show the helloworldscene(I have clean and restart the emulator).
I tried to comment the //include “helloworldscene.h”, then I get the error when I compile.
Anyone got the solution ?

Thank you.