Android, Game doesn't minimize when pressing power.

HI, When my Android game is running and I press the power button on my phone, the screen goes black (of course). However, When i press power again, the screen comes on and the game is still running. Normally, If i press power to make the screen shut off, then press power again, the screen comes on and it's asking me for my password.

The question is, how do I minimize the game when the user presses the power button. I basically want to simulate the same thing that happens when the user presses the home button.

Thanks!