Help!

#StaffMode Beta 1.0 by SamitoDee

on load:
console command "/gamerule commandBlockOutput false"
broadcast "&c(&aStaff&c) &fThe skript &6Staff v1.0 &fhas been loaded!"

command /staff <string>:
permission: staff.use
permission message: &c(&aStaff&c) &fThis requires &7(&aHelper&7)
trigger:
arg 1 is "on"
broadcast "&9[Staff] &b%player% has entered Staff Mode"
hide the player from all players
send "&c(&aStaff&c) &fStaffMode has been &aenabled&f."
apply speed to player for 999 days
arg 1 is "off"
reveal the player from all players
send "&c(&aStaff&c) &fStaffMode has been &cdisabled&f."


on join:
player has permission "staff.use"
player command "/staff on"
send "&c(&aStaff&c) &fSince you're &7(&aHelper&7)&f+, you are automatically put into Staff-Mode"
loop all players:
player has "staff.message.recieve"
send "&9[Staff] &b%player% has joined the server!"

on quit:
loop all players:
player has permission "staff.message.recieve"
send "&9[Staff] &b%player% has left the server."

command /staffchat <text>:
aliases: sc
permission: staff.chat
permission message: &c(&aStaff&c) &fThis requires &7(&aHelper&7)
trigger:
loop all players:
player has permission "staff.chat"
send "&c(&aStaff&c) &7%player%&f: &6%arg-1%"

command /about StaffMode:
trigger:
send "&c*()*()* &aStaff &c*()*()*"
send "&fAuthor: &aSamitoDee"
send "&fSpigot: &aTrue"
send "&fSkript: &aTrue"



(The hide and reveal players wont work in the command "/staff on" and "/staff off")

 

cant understand this condition or event: reveal player from all player's


cant understand this condition or event: hide player from all player's