If statement not working correctly?

local b = script.Parent
local guess = b.Parent.Guess
local nums = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"}
local plr = b.Parent.Parent.Parent.Parent
local newNum = nums[math.random(1, #nums)]
local round = 1
local submitted = false
local val = 1

b.MouseButton1Click:connect(function()
submitted = true
    if guess.Text == newNum then
        b.Parent["Yes/No"].Text = "Correct!"
        plr.Guesses.Value = plr.Guesses.Value + val
    else
        b.Parent["Yes/No"].Text = "Incorrect!"
        plr.Fails.Value = plr.Fails.Value + val
    end
end)

if submitted == true then
    val = 0
end

while true do
    wait(15)
    round = round + 1
    newNum = nums[math.random(1, #nums)]
    print(newNum)
    val = 1
end

All of that works but if I try and stop the changing of the values if the submitted is true it doesn't work. Help?

So I want to, basically, after they click once they can't click again, but when a new round starts, they can.