stuck in a game

Well I am not sure if this topic goes here but I can think in which section goes ._.Well, I am not sure is I am stupid or something but someone can please tell how to close the emulator.... I mean how to close the ds. For example in trace memory or in the legend of zelda you must close the ds for make some action. someone can tell how please

minimise the emulator for a few seconds.

huh? really thanks I owe you one(or two?) well thank you very much