PlayerAdded Not working How Do I Fix This?This Should Detect players When They Join

Hey There!Im Sorry If Im getting Too Many Errors Lately But Im Just New So When The Script Gets 2 The Line Of script Containing My "PlayerAdded" Script The Whole script Stops Like When I play The Game And I Press The Button Nothing Works Tried Even printing After The PlayerAdded Here Is The Portion Of The Code: (keep In mind I Dont Have Any Variables Cointaning "Plr" So Yea)

Players.PlayerAdded:Connect(function(player)
	print("PlayerJoined")
button.MouseButton1Click:Connect(function()--when a player presses the button in left click
		script.Parent.Parent.Visible = false-- should invis the frame
		print("Pressed")-- when a player presses the button then it will print out "Pressed"
	end)
end)

Thanks!

Have you defined "button" also, i'd recommend using WaitForChild

local S = game.Players.LocalPlayer.PlayerGui.GUINAME.FRAMENAME:WaitForChild("Nameofbutton")

-- after its done

S.MouseButton1Down:Connect(function()
-- script
end)

The Full Script Is Here:

--Variables--
local Players = game:GetService("Players")
local button = script.Parent-- gets the button
print("VariablesDone!")--prints "VariablesDone!"
--MainScript--
Players.PlayerAdded:Connect(function(plr)
	print("playerJoined")
button.MouseButton1Click:Connect(function()--when a player presses the button in left click
		script.Parent.Parent.Visible = false
		print("Pressed")-- when a player presses the button then it will print out "Pressed"
	end)
end)

ThankYou! HopeFully You Will Understand it Better now