[Roberto80]

#if is used alot in includes,like:
#if !defined Color_White
#define Color_White -1
#endif
So here,in some includes,if you don't define color white,it will define it automatically and end the if!
So same for filterscript:
#if defined FILTERSCRIPT
public onfilterscript init bla bla bla
#else (if not)
public ongamemode init bla bla bla
#endif