SubClassing

SetWindowSubclass hwnd,SubClassProc&,1,0

 SubClassProc(Byval hwnd as Longptr,Byval uMsg As Long,Byval wParam as LongPtr,Byval lParam As LongPtr,Byval uId As Long,Byval dwRef as Long) As LongPtr

DefSubClassProc Hwnd,uMsg,wParam,lParam

RemoveWindowSubClass hwnd,SubClassProc&,1

GWL_WNDPROC=-4

lpfnOld=SetWindowLongA(hwnd,GWL_WNDPROC,Address

( Of WndProc

(Of WNDProc

   ( GetPropA hwnd,lPstring       (Retrieve A Data Handle 

SetPropA hwnd,lPstring,hData

RemovePropA hwnd,lPstring 

WndPro(Byval hwnd as LongPtr,Byval uMsg

 as Long,Byval wParam as LongPtr,Byval lParam as LongPtr) As LongPtr

Select Case uMsg

Case WM_NCDESTROY ' &H82

  Call UnSubClass( hwnd)   'Built-In Function

End Select

)WndProc=CallWindowProcA

((GetPropA(hwnd,OldWndProc),hwnd,uMsg,wParam,lParam