? My timer's text isn't changing even though the if statement works! (ANSWERED)

I have a a clock gui that counts down, it's unfinished, but this is what I have so far

local seconds = 160
local minutes = math.floor(seconds/60)--Round down
local percentage = seconds%60
local clock = script.Parent.Text

for i = 1, percentage do
    wait(1)
    sec = percentage-i
    print(percentage, i, seconds, percentage-i)
    if percentage-i < 10 then
        print(1)
        clock = "0"..minutes..":0"..sec
    else        
        print(2)
        clock = "0"..minutes..":"..sec
    end
end

The output after it's done is:

40 1 160 39
2
40 2 160 38
2
40 3 160 37
2
.
.
.
40 37 160 3
1
40 38 160 2
1
40 39 160 1
1
40 40 160 0
1

but the timer is still the same: 0:00 I don't know why it isn't changing, when the if statement is working, everything else inside the if statement seem to be firing, but the code to change the time. Please help me