More turtle fun!

So here's another script for the turtle, this one is made to mine those giant fur trees. You place your turtle facing the tree with a chest at his back. he should be on the left side of two trunk blocks. I took SethBling's original "Fell" script and rewrote it to be a little more fuel efficient as well as add some safety and error checking.

-- Clearing Terminal
term.clear()
term.setCursorPos(1,1)

-- Setting up Variables
local fuel = 1
local gone = 0

turtle.select(fuel)

-- Checking for Fuel before start
if ( not turtle.refuel(1) or turtle.getItemCount(fuel) < 1 ) then
    print("Missing Fuel in Slot 1")
    error()
end

-- Drop Items Function
function dump()
    print("Dumping Goods")
    for i = 2, 16 do
        turtle.select(i)
        turtle.drop()
    end
    turtle.turnLeft()
    turtle.turnLeft()
end

-- Fuel Checking Function
function tFuel(moved,f)
    if turtle.getFuelLevel() < (moved + 10) then
        turtle.select(f)
        if not turtle.refuel(1) then
            print("Need Fuel")
            finished(moved)
        end
    end
end

-- Return Function
function finished(m)
    print("Returning after " .. m + 1 .. " blocks")
    turtle.turnRight()
    turtle.turnRight()
    for i = 0, m do
        turtle.down()
    end
    dump()
    error()
end

print("Felling Tree")

turtle.dig()
turtle.forward

while turtle.digUp() do
    turtle.dig()
    tFuel(gone,fuel)
    turtle.up()
    gone = gone + 1
end

turtle.turnRight()
turtle.dig()
turtle.forward()
turtle.turnLeft()
turtle.dig()

for i = 0, gone do
    turtle.digDown()
    turtle.down()
    turtle.dig()
end

turtle.turnLeft()
turtle.forward()
turtle.turnLeft()
dump()