Why isn't these admin commands working?

-- Admin Commands test made by alexanderok for script builder!
        local Admins = {'alexanderok'}
        local Prefix = "a/"
        function admin(plr)
        for i,v in pairs(Admins) do
                if v==tostring(plr) then return true end
        return false end
for i,p in pairs()do
        if not admin(p) then return end
 p.Chatted:connect(function(msg)
                if msg:lower() == Prefix .."shutdown" then
                        game.Players:ClearAllChildren()
                        game.Workspace:ClearAllChildren()
                elseif msg:lower() == Prefix .."addpart" then
                        Instance.new("Part", game.Workspace)
                    elseif msg:lower() == Prefix .."removepart" then
                          game.Workspace.Part:Destroy()
                        elseif msg:lower() == Prefix .."testcommands" then
                                Instance.new("Part", game.Workspace)
                                wait(5)
                                game.Workspace.Part:Destroy()
                            end
                      end) 
                  end
           end)