Download this and open it with Pawno. Make sure you have zcmd.inc in your pawno/includes. Then when you compiled it copy policeflash.amx to your 'filterscripts' folder! Then go to your server.cfg and where it says filterscripts add policeflash!
Thanks, I did everything as you say. When I type /flash, it says that this cmd is not in the database. Must I insert something in the gamemode?
EDIT: It works. Thanks