Android Emulator：选择AVD（Android虚拟设备）默认运行

I have added a second Virtual Device to test a different screen resolution (QVGA), but now I wanna switch back to the first AVD (HVGA) again. How can I set the virtual device in Eclipse to be used by default or even specifically for my project? In the properties I can only set the API level.I have added a second Virtual Device to test a