Does anyone know how to fix a local variable script?

Hello, I finished Jhxan's Self Check In tutorial and I am done! This is the final result of the handler and I have one error. He has not responded yet so I have asked here. The 2nd line doesn't not respond right. Does anyone know what to do?

local gui = script.Parent
local mFrame = gui:WaitForChild("mFrame")
local classFrame = mFrame:WaitForChild("classFrame")
local lastFrame = mFrame:WaitForChild("lastFrame")
local startFrame = mFrame:WaitForChild("startFrame")
local plr = Game.GetService("Players").LocalPlayer
local re = Game.GetService("ReplicatedStorage"):WaitForChild("scRE")
local ecShirtID = 0
local premiumShirtID = 1226638237
local proShirtID = 1228336480


script:WaitForChild("uid").Value = game:GetService("HttpService"):GenerateGUID()

--prevent duplication of mFrame
for i,v in pairs (plr.PlayerGui:GetChildren()) do
    if v:IsA("ScreenGui") then
        if v:FirstFindChild ("scHandler") then
            if v.scHandler.uid.Value == script:WaitForChild("uid") then
                v:Remove()
            end
        end
    end
end

--button detections

for i,btn in pairs (classFrame:GetChildren()) do
    if btn:IsA("TextButton") then
        btn.MouseButton1Down:Connect(function()
            local card = btn:WaitForChild("cardName").Value

            if card == "Catopa Economy" then
               if ecShirtID = 0 then
                game:GetService("MarketplaceService"):PlayerOwnsAsset(plr, ecShirtID) then
                    else

                    return

             if card == "Catopa Premium" then
               if premiumShirtID = 1226638237 then
                game:GetService("MarketplaceService"):PlayerOwnsAsset(plr, premiumShirtID) then
                    else

                    return

             if card == "Catopa Pro" then
               if proShirtID = 1228336480 then
                game:GetService("MarketplaceService"):PlayerOwnsAsset(plr, proShirtID) then
                    else

                    return          

            re:FireServer("giveCard", card)
            classFrame.Visible = false
            lastFrame.Visible = true
        end)
    end
end

lastFrame:WaitForChild("exitBtn").MouseButton1Down:connect(function()

end)

startFrame:WaitForChild("startBtn").MouseButton1Down:connect(function()
    startFrame.Visible = false
    classFrame.Visible = true
end)

mFrame:WaitForChild("closeBtn").MouseButton1Down:connect(function()
    gui:Remove()
end)