lResult = SendMessage( 	    // returns LRESULT in lResult 	
   (HWND) hWndControl, 	    // handle to destination control 	
   (UINT) TVM_GETNEXTITEM, 	    // message ID 	
   (WPARAM) wParam, 	    // = (WPARAM) (UINT) flag;	
   (LPARAM) lParam 	    // = (LPARAM) (HTREEITEM) hitem;	
);