UU-Matter Glasses Startup 2.1

rednet.open("right")
tank1 = peripheral.wrap('openblocks_tank_1')
tank2 = peripheral.wrap('openblocks_tank_2')
tank3 = peripheral.wrap('openblocks_tank_3')
tank4 = peripheral.wrap('openblocks_tank_4')
while true do
amount = 0
--  Tank 1
tank1table = tank1.getTankInfo("right")
if tank1table[1]["amount"] ~= nil then do
amount = amount + tank1table[1]["amount"]
write(tostring(amount))
end
end
--  Tank 2
tank2table = tank2.getTankInfo("right")
if tank2table[1]["amount"] ~= nil then do
amount = amount + tank2table[1]["amount"]
write(tostring(amount))
end
end
--  Tank 3
tank3table = tank3.getTankInfo("right")
if tank3table[1]["amount"] ~= nil then do
amount = amount + tank3table[1]["amount"]
write(tostring(amount))
end
end
--  Tank 4
tank4table = tank4.getTankInfo("right")
if tank4table[1]["amount"] ~= nil then do
amount = amount + tank4table[1]["amount"]
write(tostring(amount))
end
end

--Other Funktions
rednet.broadcast(amount.."xuutanks")
os.sleep(10)
term.clear()
term.setCursorPos(1,1)
end