Added USER.DestroyIcon32 to Callout struct.

diff --git a/include/callback.h b/include/callback.h
index 64e925c..0855695 100644
--- a/include/callback.h
+++ b/include/callback.h
@@ -123,6 +123,7 @@
 
     HQUEUE16 WINAPI (*InitThreadInput16)( WORD unknown, WORD flags );
     void WINAPI (*UserYield16)( void );
+    WORD WINAPI (*DestroyIcon32)( HGLOBAL16 handle, UINT16 flags );
     
 }  CALLOUT_TABLE;