--- mstools/samples/maskblt/maskblt.h	2018/08/09 18:20:45	1.1
+++ mstools/samples/maskblt/maskblt.h	2018/08/09 18:21:44	1.1.1.2
@@ -2,8 +2,8 @@
 
 
 /* function prototypes for the window procedures. */
-LRESULT MainWndProc(HWND, UINT, WPARAM, LPARAM);
-LRESULT DlgProc    (HWND, UINT, WPARAM, LPARAM);
+LRESULT CALLBACK MainWndProc(HWND, UINT, WPARAM, LPARAM);
+LRESULT CALLBACK DlgProc    (HWND, UINT, WPARAM, LPARAM);
 
 VOID DrawGrids (HDC, int, int);
 
@@ -21,6 +21,7 @@ VOID DrawGrids (HDC, int, int);
 #define  DID_ROP0       110
 #define  DID_ROP1       111
 #define  DID_ROP2       112
+#define  DID_ROP3       113
 
 #define  DID_NEWSRC     300
 #define  DID_NEWMASK    301