title: Python 3 pyAutoGUI - I can't use screenshot functions
body: <p>I tried an import from the documentation:</p>
  
  <pre><code>import pyautgui
  pyautogui.click(pyautogui.locateOnScreen("select.png"))
  </code></pre>
  
  <p>and I get these errors in line 2:</p>
  
  <pre><code>File "C:\log\WinPython-64bit-3.5.4.0Qt5\python-3.5.4.amd64\lib\site-packages\pyscreeze\__init__.py", line 267, in locateOnScreen
  screenshotIm = screenshot(region=None) # the locateAll() function must handle cropping to return accurate coordinates, so don't pass a region here.
  
  File "C:\log\WinPython-64bit-3.5.4.0Qt5\python-3.5.4.amd64\lib\site-packages\pyscreeze\__init__.py", line 314, in _screenshot_win32
  im = ImageGrab.grab()
  
  NameError: name 'ImageGrab' is not defined
  </code></pre>
  
  <p>Could you help?</p>