title: Python win32api SendMesage
body: <p>I am trying to clarify win32api. And I just made a simple example. Get the Notepad window, move the mouse to a position, click and write a string. But it does not work. What's the problem?<br />
  And could anybody clarify for me what the lParam parameter is?<br />
  What does it do, What type is it and How should it look?</p>
  <pre><code>import win32api, win32con, win32gui, win32ui, win32service, os, time
  
  
  
  def f_click(pycwnd):
          x=300
          y=300
          lParam = y &lt;&lt;15 | x
          pycwnd.SendMessage(win32con.WM_LBUTTONDOWN, win32con.MK_LBUTTON, lParam);
          pycwnd.SendMessage(win32con.WM_LBUTTONUP, 0, lParam);
  
  def get_whndl():
          whndl = win32gui.FindWindowEx(0, 0, None, 'NB.txt - Notepad')
          return whndl
  
  def make_pycwnd(hwnd):       
          PyCWnd = win32ui.CreateWindowFromHandle(hwnd)
          return PyCWnd
          
  def send_input_hax(pycwnd, msg):
      f_click(pycwnd)
      for c in msg:
          if c == &quot;\n&quot;:
              pycwnd.SendMessage(win32con.WM_KEYDOWN, win32con.VK_RETURN, 0)
              pycwnd.SendMessage(win32con.WM_KEYUP, win32con.VK_RETURN, 0)
          else:
              pycwnd.SendMessage(win32con.WM_CHAR, ord(c), 0)
      pycwnd.UpdateWindow()
          
  whndl = get_whndl()
  pycwnd = make_pycwnd(whndl)
  msg = &quot;It works !\n&quot;
  send_input_hax(pycwnd,msg)
  </code></pre>