Help Fixing Chat Please?

I've created a chat for in game, but the problem is that the focus is never lost on the button after they click on it or press "/" to type, so they can not move around or anything because the keys show up in the chat. Anyone know why?

wait()
local storage = game.ReplicatedStorage
local players = game.Players
local remote = storage.ChatRemote
local httpservice = game:GetService("HttpService")
local ChatBox = script.Parent.ChatFrame.ChatBox
local ChatFrame = ChatBox.Parent
local player = game.Players.LocalPlayer
local Mouse = player:GetMouse()
local ChatText = ChatBox.EnterChat
local Chat = ChatFrame.T1
local Settings = {
        chatkey = "/",
        Focus = false,
        chatboxtext = [[Press "/" or Click here to chat]],
        ChatLife = math.huge,
        ChatMax = 8
    }
game:GetService("StarterGui"):SetCoreGuiEnabled("Chat",false)

ChatText.Text = Settings.chatboxtext

function Chatted(player,message,color)
    local NewChat = Chat:Clone()
    NewChat.Visible = true
    if player.Name == "RockerCaleb1234" or player.Name == "devHoodie" then
        NewChat.Text = "{Owner}["..player.Name.."]: "..message
    elseif player.Name == "AlteringEgos" then
        NewChat.Text = "{Tester}["..player.Name.."}: "..message
    else
    NewChat.Text = "["..player.Name.."]: "..message
end
    NewChat.TextColor3 = color
    NewChat.Name = player.Name
        for i,c in next,ChatFrame:GetChildren() do
        if c.Name ~= ChatBox.Name and c.Name ~= Chat.Name then
        c.Position = c.Position - UDim2.new(0,0,0.125,0)
        if c.Position.Y.Scale < 0 then
        c:Destroy()
    end
    end
    end
        NewChat.Parent = ChatFrame
        NewChat.Position = UDim2.new(0,0,.875,0)
        game:GetService("Debris"):AddItem(NewChat,Settings.ChatLife)
end


Mouse.KeyUp:connect(function(key)
    if key == Settings.chatkey then
        ChatText.Text = ""
    end
    ChatText:CaptureFocus()
end)


ChatText.FocusLost:connect(function(entered)
        if not entered and Settings.Focus then
        ChatText.Text = Settings.chatboxtext
        elseif entered then
        if ChatText.Text == "" then
        ChatText.Text = Settings.chatboxtext
        else
            remote:FireServer(ChatText.Text)    
    end
    end
end)



remote.OnClientEvent:connect(function(player,message,color)
    Chatted(player,message,color)
end)