Lumberjack

ffunction refuel()
    while turtle.getItemCount(1) ~=0 and turtle.getFuelLevel() < 200 do
    turtle.select(1)
    turtle.refuel(1)
    end

    if turtle.getFuelLevel() == 0 and turtle.getItemCount(1) == 0 then
        return true
    else
        return false
    end

end

if turtle.getFuelLevel() then
        return("Out of Fuel")
end

function needFuel()
    if turtle.getFuelLevel() < 10 then
        return true
    else
        return false
    end
end

function digForward()
    while turtle.detect() do
        turtle.dig()
    end
end

function digUp()
    while turtle.detect() do
        digForward()
        print("Digging the block")
        turtle.up()
        print("Is this the Jeffersons? Cuz we movin' on up")
    end

    while not turtle.detect() and not turtle.detectDown() do
        turtle.down()
        print("Next stop, the basement!")
    end
end

function moveForward()
    if needFuel() then
    refuel()
        else
            print("Out of Fuel")
    end

    while turtle.forward() == false do
    digForward()
    turtle.attack()
    digUp()
    end
end

moveForward()