Cocos2d-Phone 场景切换及动画效果
    CCTransition* transition =[CCTransition transitionFadeWithDuration:1.5];
    [[CCDirector sharedDirector] replaceScene:[CCBReader loadAsScene:@"MainScene"]withTransition:transition];    CCTransition* transition =[CCTransition transitionFadeWithDuration:1.5];
    [[CCDirector sharedDirector] replaceScene:[CCBReader loadAsScene:@"MainScene"]withTransition:transition];