How do I make a gui disappear, that was activated by dialog, to disappear when a player walks away?

I'm able to make the gui appear when a player responds to the NPC, but I can't seem to figure out how to make the gui disappear automatically when a player walks away from the conversation.

Dialog = script.Parent
Dialog.DialogChoiceSelected:connect(function(player,dialog)
    local ShopScreen = script.Parent.ShopScreen
    if dialog.Name == "OpenShop" then
        ShopScreen:Clone().Parent = player.PlayerGui
        local ShopScreenClone = player.PlayerGui.ShopScreen
        Background = ShopScreenClone.Background
        Features = ShopScreenClone.Features
        for i, child in pairs(ShopScreenClone:GetChildren()) do
            child.Visible = true
        end
        Background:TweenSizeAndPosition(UDim2.new(0, 400, 0, 400), UDim2.new(0.292, 0,0.081, 0), "In", "Quad", 2)
        wait(0.5)
        Features:TweenPosition(UDim2.new(0.294, 0,0.104, 0), "Out", "Quad", 0.5)
    end
end)
if Dialog.InUse == false then
    Background:TweenSizeAndPosition(UDim2.new(0, 0, 0, 0), UDim2.new(0.292, 0,0.081, 0), "In", "Quad", 2)
    Features:TweenPosition(UDim2.new(-1, 0,0.104, 0), "Out", "Quad", 0.5)
end