[Lordzy]

Not bad as this is your first fs.
But, I saw that you're using [256] as cells size.
A normal client message sends up to 128 only, so it's better changing it to 128.

pawn Code:

//Eg:
new str[128];
new Lname[MAX_PLAYER_NAME];
GetPlayerName(playerid,Lname,sizeof(Lname));
format(str,sizeof(str),"%s says 128 is the normal size used for a client message.", Lname);
SendClientMessage(playerid, -1, str);