Computercraft Vending System V1

os.pullEvent = os.pullEventRaw
side2 = "back"
term.clear()
term.setCursorPos(1,1)
print("Please Insert Vend Pass")
event, side = os.pullEvent("disk")
print("Pass Inserted")
print("Beginning Security Check")
sleep(0.5)
if fs.exists("disk/startup") then
        term.setTextColor(colors.red)
        print("WARNING: Startup Program Detected!")
        c = 0
        while tk == 1 do
            -- If a program called startup_#### doesn't exist then:
            if not fs.exists("startup_" .. c) then
                -- resets security variable
                tk = 0
                -- stores a copy of the startup program to the computer as "startup_####"
                shell.run("copy disk/startup", "startup_" .. c)
            else
                -- Increases the number by 1
                sleep(0.1)
                c = c + 1
            end
        -- Deletes the startup program on the floppy disk
        shell.run("delete disk/startup")
        print("Program logged and deleted!")
        sleep(0.5)
        print("Confiscating disk...")
        sleep(0.5)
        -- Ejects disk then reboots the computer
        disk.eject(side)
        os.reboot()
        end
    end
    -- Checks if a data disk was inserted or if a random object was inserted instead
    if not disk.hasData(side) then
        term.setTextColor(colors.red)
        print("Warning: Invalid Object Detected!")
        sleep(0.5)
        print("Confiscating item. Please see zoo staff for retrieval")
        sleep(2)
        disk.eject("bottom")
        os.reboot()
    end
    if not fs.exists("disk/.credits") then
        term.setTextColor(colors.red)
        print("Disk doesn't have credit pass data!")
        sleep(0.5)
        print("Confiscating disk. Please see zoo staff for retrieval")
        sleep(2)
        disk.eject("bottom")
        os.reboot()
    end
rID = disk.getID(side)
    if rID == 5 or rID == 11 then
        term.setTextColor(colors.red)
        term.clear()
        term.setCursorPos(1,1)
        print("Admin Card Detected")
        print("Additional Options Unlocked")
        sleep(2)
    end
while true do

    --Checks Balance
    creditDat = fs.open("disk/.credits","r")
    credits2 = creditDat.readLine()
    creditDat.close()

    -- Main Screen
    term.clear()
    term.setCursorPos(1,1)
    term.setTextColor(colors.yellow)
    print("Condemned Zoo Vending Machine System V1\n ")
    credits = tonumber(credits2)
    print("You currently have ".. credits .." credits on your card")
    if credits > 0 then
        print("Please select your requested item #")
        print("1 - Splash Health Potion II - 50 credits")
        print("2 - Saddles - 10 credits")
        print("3 - Diamond Horse Armor - 20 credits")
        print("4 - End Transaction")
        if rID == 5 or rID == 11 then
            term.setTextColor(colors.orange)
            print("5 - Enter Maintenance Mode")
        end
        term.setTextColor(colors.yellow)
        input = read()
        if input == "1" then
            if rs.testBundledInput(side2, colors.lime) == false then
                if credits >= 50 then
                    credits = credits - 50
                    creditUp = fs.open("disk/.credits","w")
                    creditUp.writeLine(credits)
                    creditUp.close()
                    print("Now Vending Item 1")
                    rs.setBundledOutput(side2, colors.white)
                    sleep(0.1)
                    rs.setBundledOutput(side2, 0)
                    sleep(1)
                    print("Check chest for item")
                    sleep(2)
                 end
            else
                term.setTextColor(colors.red)
                print("Sold Out :(")
                sleep(2)
            end
        elseif input == "2" then
            if rs.testBundledInput(side2, colors.pink) == false then
                if credits >= 10 then
                    credits = credits - 10
                    creditUp = fs.open("disk/.credits","w")
                    creditUp.writeLine(credits)
                    creditUp.close()
                    print("Now Vending Item 2")
                    rs.setBundledOutput(side2, colors.orange)
                    sleep(0.1)
                    rs.setBundledOutput(side2, 0)
                    sleep(1)
                    print("Check chest for item")
                    sleep(2)
                 end
            else
                term.setTextColor(colors.red)
                print("Sold Out :(")
                sleep(2)
            end
        elseif input == "3" then
            if rs.testBundledInput(side2, colors.gray) == false then
                if credits >= 20 then
                    credits = credits - 20
                    creditUp = fs.open("disk/.credits","w")
                    creditUp.writeLine(credits)
                    creditUp.close()
                    print("Now Vending Item 3")
                    rs.setBundledOutput(side2, colors.magenta)
                    sleep(0.1)
                    rs.setBundledOutput(side2, 0)
                    sleep(1)
                    print("Check chest for item")
                    sleep(2)
                 end
            else
                term.setTextColor(colors.red)
                print("Sold Out :(")
                sleep(2)
            end
        elseif input == "4" then
            term.clear()
            term.setCursorPos(1,1)
            print("Thank you for using the condemned zoo vending system")
            print("Don't forget to take your pass")
            sleep(5)
            print("Auto ejecting pass")
            sleep(2)
            disk.eject(side)
            os.reboot()
        elseif input == "5" and (rID == 5 or rID == 11) then
            print("Entering Maintenance Mode")
            break
        else
            term.setTextColor(colors.red)
            print("Invalid Selection")
            sleep(2)
        end

    else
        term.setTextColor(colors.red)
        print("You are out of credits")
        disk.setLabel(side,"Empty Pass")
        sleep(0.5)
        print("Confiscating empty pass")
        sleep(0.5)
        print("See guest services for a new credit pass")
        sleep(2)
        disk.eject(side)
        os.reboot()
    end
end