-char* wxFileSelector(const char *message = wxFileSelectorPromptStr, const char *default_path = NULL,
- const char *default_filename = NULL, const char *default_extension = NULL,
+char* wxFileSelector(const char *message = wxFileSelectorPromptStr, const char *default_path = (const char *) NULL,
+ const char *default_filename = (const char *) NULL, const char *default_extension = (const char *) NULL,