function Name(existing, new)
if game.Players[existing].Character == true then
game.Players[existing].Character.Name = new
end
end

Name("gunkillerguner", "Guest 1")
Name("djwhizzkid", "your helper")
Name("telamon", "1337")
Name("ROBLOX", "ROBLOX - OWNS!")
Name("builderman", "I build things, i do!")