This is wrong in the source:
BBDECL void GIZMessageBox(char *messagetodisplay, char *title)
Should be:
BBDECL void GIZMessageBox(const char *messagetodisplay, const char *title)
BBDECL void GIZMessageBox(char *messagetodisplay, char *title)
Should be:
BBDECL void GIZMessageBox(const char *messagetodisplay, const char *title)