Why is my string value not changing?

Hi. I have a localscript which is inside a Gui. When you select one of two buttons on the ScreenGui, it should update the value of a StringValue in ReplicatedStorage.

This is my script:

local Bristol = script.Parent
local MintCreek = script.Parent.Parent.MintCreek
local Data = game.ReplicatedStorage.CheckInBoards.Lane1.Destination.Value

script.Parent.MouseButton1Click:Connect(function()
	-- Select Bristol
	Bristol.BackgroundColor3 = Color3.fromRGB(12, 76, 153)
	Bristol.AutoButtonColor = false
	Bristol.Selectable = false
	Data = "BristolDest"
	
	-- Change MintCreek
	MintCreek.AutoButtonColor = false
	MintCreek.Selectable = false
	MintCreek.LocalScript:Destroy()
end)`

Any help would be greatly appriciated.

Thanks in advance, Timothy