Unanswered: sencha touch using android application

Hi.,am a beginner for both Android Applications and sencha-touch.so i wish to learn developing hello world application on android using sencha-touch.please explain step by step process for beginers.then tell me what is advantages for using these.also guide me connecting mysql database using sencha-touch and calling ajax function in android.how is run these application on android emulator also.please guide me…