- // check if we can use FlashWindowEx(): unfortunately an explicit test for
- // FLASHW_STOP, for example, doesn't work because MSVC6 headers do #define
- // it but don't provide FlashWindowEx() declaration
-#if (WINVER >= 0x0500 && (defined FLASHW_STOP))
+ // check if we can use FlashWindowEx(): unfortunately a simple test for
+ // FLASHW_STOP doesn't work because MSVC6 headers do #define it but don't
+ // provide FlashWindowEx() declaration, so try to detect whether we have
+ // real headers for WINVER 0x0500 by checking for existence of a symbol not
+ // declated in MSVC6 header
+#if defined(FLASHW_STOP) && defined(VK_XBUTTON1)