[Lua] [Error] Disk:3 String Expected in my SlimeOS Login program...

os.loadAPI("/slimeos/apis/colourtxt")
while true do
function getDiskSide()
  sides = {"back","right","left","top","bottom"}
  for i=1, #sides do
   if disk.isPresent(sides[i]) and disk.getMountPath(perikit.sides[i]) == "/disk" then
	return perikit.sides[i]
   end
  end
end

term.clear()
term.setCursorPos(1,1)
colourtxt.printColour("SlimeOS Login Screen:", colours.white, colours.green)
colourtxt.printColour("What do you want to do?", colours.white, colours.blue)
print(" [1] Login with current disk")
print(" [2] Create new user with current disk")
print(" [3] Shutdown")
print("")
term.setTextColour(colours.yellow)
write("> ")
term.setTextColour(colours.white)
input = read()
if input == "1" then

elseif input == "2" then
  if not fs.exists("/disk/,") then
   --files = fs.list("/disk")
   --for i=1, #files do
   -- fs.delete(files[i])
   --end
   write("Username: ")
   usr = read()
   write("Password: ")
   pass1 = read("*")
   write("Confirm Password: ")
   pass2 = read("*")
   if pass1 == pass2 then
	print("Writing Data...")
	file = fs.open("/disk/,", "w")
	file.writeLine(pass2)
	disk.setLabel(getDiskSide(), usr)
	print("Data Written! Please Login:")
	sleep(2)
	file.close()
   else
	colourtxt.printColour("Passwords don't match!", colours.white, colours.red)
	sleep(2)
   end
  else
	colourtxt.printColour("Disk is already a user.",colours.white, colours.red)
	sleep(2)
  end
  elseif input == "3" then
  print("Goodbye")
  sleep(1)
  os.shutdown()
end
end

function printColour(text, oldcolour,newcolour)
--default = term.getTextColour()
term.setTextColour(newcolour)
print(text)
term.setTextColour(oldcolour)
end

sides = {"back","right","left","top","bottom"}
function getDiskSide()
    for i=1, #sides do
        if disk.isPresent(sides[i]) and disk.getMountPath(sides[i]) == "disk" then
            return sides[i]
        end
    end
end

function clean()
    term.setCursorPos(1,8) term.clearLine()
    term.setTextColour(colours.yellow)
    write("> ")
    r = read()
    term.setCursorPos(1,10) term.clearLine()
    term.setTextColour(colours.red)
    return r
end

term.clear()
term.setCursorPos(1,1)
term.setTextColour(colors.lightGray) print(" SlimeOS Login Screen:")
print(" What do you want to do?")
term.setTextColour(colours.red) print(" [1] Login with current disk")
print(" [2] Create new user with current disk")
print(" [3] Shutdown")
term.setTextColour(colours.yellow) print("Please type 1, 2 or 3")

while true do
    input = clean()
    if input == "1" then

    elseif input == "2" then
        if getDiskSide() then
            if not disk.getLabel(getDiskSide()) then
                --files = fs.list("/disk")
                --for i=1, #files do
                -- fs.delete(files[i])
                --end
                write("Username: ")
                usr = read()
                write("Password: ")
                pass1 = read("*")
                write("Confirm Password: ")
                pass2 = read("*")
                if pass1 == pass2 then
                    print("Writing Data...")
                    file = fs.open("/disk/"..usr, "w")
                    file.write(pass2)
                    file.close()
                    disk.setLabel(getDiskSide(), usr)
                    print("Data Written! Please Login:")
                    sleep(2)
                else
                    print("Passwords don't match!")
                    sleep(2)
                end
            else
                print("Disk is already a user.")
                sleep(2)
            end
        else
            print("No disk!")
            sleep(2)
        end
    elseif input == "3" then
        print("Goodbye")
        sleep(1)
        os.shutdown()
    end
end

-- Clean up
term.clear()
term.setCursorPos(1,1)
term.setTextColour(colours.white)