How to shutdown a game for a player?

What this is supposed to be for is for banned players, kicked players, etc. So far, I've created this function:

local Banned = {}

function isPlayerBanned(BanChk)
	for i, v in pairs(Banned) do
		if Banned == v then
			return true
		end
	end
end

game.Players.PlayerAdded:connect(function(newplayer)
	if playerBanned(newplayer.Name) then

The problem I get after the 12th line is that I don't know how to shutdown a player. Not remove their character so they can't spawn or interact with anything, but genuinely make the "game shutdown" message pop up for them so that all instances have stopped for them. Any help?

This should help: http://wiki.roblox.com/index.php?title=API:Class/Player/Kick

Disconnects their client so it would essentially shutdown the game for them. The final product would be:

local banned = {}

function isPlayerBanned(player)
	for int, val in pairs(banned) do
		if val == banned then
			return true
		else
			return false
		end
	end
end

game.Players.PlayerAdded:connect(function(player)
	if isPlayerBanned(player) then
		player:Kick()
	end
end)

local Banned = {}

function isPlayerBanned(BanChk) for i, v in pairs(Banned) do if Banned == v then return true end end end

game.Players.PlayerAdded:connect(function(newplayer) if playerBanned(newplayer.Name) then newplayer:Kick("Banned") end end)