How do I prevent Guis from cloning the same Gui twice?

So uh I have an inventory script and a backpack gui. Everything functions however in this link you will see a weird bug where all the items cloned twice. Does anyone know how to delete extra clones?

https://gyazo.com/22c8c5ba3b43124ef87678666f3f45cf

this is the backpack script:

local player = game.Players.LocalPlayer
local character = player.Character
local items = {}
local buttons = {}
game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Backpack,false) -- Makes the original backpack gui invisible

function search()
	for i,v in pairs(game.Players.LocalPlayer.Backpack:GetChildren()) do -- Find all item in a specific location
		if v:isA("Tool") then -- If the item found is a "Tool"
			table.insert(items,v) -- We're going to put all the tools found in a table.
		end
	end
end

function refresh()
	for i,v in pairs(buttons) do -- Finds all items in the table
		v:Destroy() -- Destroy 'em all
	end
	for i,v in pairs(items) do -- Finds all items in the table
		local button = script.Sample:Clone() -- clones the sample button inside the localscript
		button.Name = v.Name -- sets the cloned button's name to the name of the item
		button.LayoutOrder = i
		button.Parent = script.Parent.Handler -- Sets the parent of the cloned button to the handler
		button.Image = v.TextureId -- Sets the image of the button to the texture id of the tool
		button.ZIndex = 7
		button.BackgroundColor3 = Color3.fromRGB(50,50,50)
		button.BorderColor3 = Color3.fromRGB(25,25,25)
		button.BorderMode = Enum.BorderMode.Inset
		button.BorderSizePixel = 5
		table.insert(buttons,button) -- Inserts the button to our table "buttons"
		button.MouseButton1Click:connect(function()
			if script.Parent.Handler.Selected.Value == nil or script.Parent.Handler.Selected.Value ~= v then -- Checks if the selected value is nothing or if the selected value is not the button
				script.Parent.Frame.ItemName.Text = v.Name -- Sets the TextLabel's Text to the name of the tool/button
				script.Parent.Frame.ImageLabel.Image = v.TextureId -- Sets the image label's image to the texture id of the tool
				script.Parent.Handler.Selected.Value = v
				if script.Parent.Handler.Selected.Value ~= script.Parent.Handler.Equipped.Value then --if the selected value is not the same as the equipped value then
					script.Parent.Handler.Location.Value = v.Parent -- Sets the value of our location to the parent of the tool whether it is in the backpack or in the character
					script.Parent.Frame.Equip.Text = "Equip" -- Self explanatory
				elseif script.Parent.Handler.Selected.Value == script.Parent.Handler.Equipped.Value then -- If the selected value is the same as the equipped value then...
					script.Parent.Handler.Location.Value = v.Parent
					script.Parent.Frame.Equip.Text = "Unequip"
				end
			end
		end)
	end
end

function backpackRefresh()
	items = {}
	search(character)
	search(player.Backpack)
	refresh()
end

backpackRefresh()

player.Backpack.ChildAdded:connect(backpackRefresh)
player.Backpack.ChildRemoved:connect(backpackRefresh)

character.ChildAdded:connect(backpackRefresh)
character.ChildRemoved:connect(backpackRefresh)