Menu Windows Moving in Windows

[S.J.Chun]

Hi, attached file is my simple testing code of NSMenu related drawing in 
GNUstepBack bundle. Currently I cannot move
NSMenu window CORRECTLY. I think we should add similar logic of my attached 
file when WM_LBUTTONDOWN case.
My idea is, if we can know whether current window is menu (from hwnd) and 
current position of buttondown is in the
menu title then do SendMessage(...). Am I wrong ? If this is right, can anyone 
let me know how can I know whether
this hwnd is for Menu or not ?

Thanks in advance.