to start with,
PHP Code:
pl.chat = format("", player.account);
player.chat = format("", pl.communityname);
wont work, because you won't chat the account/communityname because there is no %s in the first parameter.
edit:
2nd, there's a space after //#CLIENTSIDE, remove that and the trigger will work.
3rd, there's no reason to have "&& player.account != NULL" since it's not possible to have no account and be a player chatting "/summon" !