   petzold error?
  "WinMain calls ShowWindow, Windows sends the window procedure WM_SIZE and WM_SHOWWINDOW messages"  -- petzold programming windows.I did it and found no WM_SHOWWINDOW sent.another question:if you call ShowWindow() twice, and the 2nd will not sent WM_SHOWWINDOW.for example:ShowWindow()UpdateWindow();ShowWindow(); // no WM_SHOWWINDOW   
  Try WM_SHOW, I am not aware of a WM_SHOWWINDOW.Hope that helps.   ;  It's WM_SHOW.   ;  It's WM_SHOWEdit: Owh, I got beaten >_<   ;  if you look at msdn ,just wm_showwindow no wm_show.when I replace wm_showwindow with wm_show in app wizard generated code(should no error), compiler said no WM_SHOW found. I am use chinese version vc2003,does it matter?   ;  #define WM_SHOWWINDOW24WM_SHOWWINDOWThere is no WM_SHOW message. ShowWindow is probably better understood as "set window show state" - that is, it changes a state flag, but doesn't necessarily activate the display.   