BOOL pascal EnumWindows(BOOL (pascal *func)(), DWORD lParam)

  This function will call the passed function for every window in the
window system with the handle of the window and the passed lParam as
the arguments. The function will be called with the arguments (hWnd,
lParam). If any call of 'func' returns FALSE, then EnumWindows() will
return immediately without processing the rest of the windows.

Parameters
  func is a pointer the function which will be called for each window.
  lParam will be passed as the second argument to that function.

Returns
  TRUE if hParent was a valid window handle, FALSE if not.