Lua CC Simple wall

x = 16
z = 8
function update()
    shell.run("pastebin", "get", "YhK59cm5", "blockCheck")
    shell.run("pastebin", "get", "2EkpdDpX", "fuelCheck")
end
function doubleCheck()
    print("Checking fuel and blocks...")
    shell.run("blockCheck")
    shell.run("fuelCheck")
    turtle.select(1)
end
function slab()
    for i = 1, x, 1 do
        turtle.up()
        turtle.placeDown()
    end
end
update()
turtle.forward()
for i = 1, z, 1 do
    slab()
    doubleCheck()
    turtle.forward()
    for i = 1, x, 1 do
        turtle.down()
    end
end
turtle.turnLeft()
turtle.forward()
turtle.turnLeft()
for i = 0, z, 1 do
    turtle.forward()
end
turtle.turnLeft()
turtle.forward()
turtle.turnLeft()