Tests whether a window is a child window of a specified parent window
#include <WinAPISysWin.au3>
_WinAPI_IsChild ( $hWnd, $hWndParent )
| $hWnd | Handle to the window to be tested. |
| $hWndParent | Handle to the parent window. |
| True: | the window is a child window of the specified parent window. |
| False: | the window is not a child window of the specified parent window. |
Search IsChild in MSDN Library.