A simple "Take Screenshot" function, easy to impliment into your own program just by adding it to the main loop.

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    if keystate(88)=1
      screenshot = 0
      repeat
         INC screenshot
      until FILE EXIST("ScreenShots/Screenshot Number - " + STR$(screenshot) + ".jpg") <> 1
      img = FIND FREE IMAGE()
      GET IMAGE img, 0, 0, SCREEN WIDTH(), SCREEN HEIGHT(), 1
      SAVE IMAGE "/ScreenShots/Screenshot Number - " + STR$(screenshot) + ".jpg", img
      DELETE IMAGE img
endif