I'm writing an app that can play flash on android, but I can't simulate ESC key, since a lot of flash games need ESC key to return to the main menu, without this key the app I made will be useless. So who could tell me how to simulate this? Can I just send a keycode? but I don't know the keycode too...
Most games use the BACK key for this.... See http://developer.android.com/sdk/android-2.0.html
Note that, while there is a key event ESCAPE (as Ezeh points out), that is only available at API level 11 (which is Android 3.0 and above - http://developer.android.com/guide/appendix/api-levels.html), which is not very widely available in devices yet.