Automated tree farming

[Edit 1] I followed mitterdoo's great suggestion of using pastebin.

Hey, this is my first automated tree farming turtle, it works on a flat surface and uses three chests, one for the gathered wood, one for a sapling supply and one for a bonemeal supply.
At the moment I use birch trees because they cannot spawn branches, and the script is (at the moment, for the future, who knows) suitable for branches.

The number of rows and the number of tree's in a row is variable, even though i didn't prompt the user for it. (again, who knows what the future brings).

Feel free to use the script for your wood supply needs. It automatically lays down dirt and replaces saplings.

If you find a bug in the script please tell me. As of now i know one bug, namely it sometimes replaces saplings. I think it's due to the growth of the saplings, I don't know. Anyways, have fun with it!

For the chest layout. (x is air, s is the sapling chest, b is the bonemeal chest, w is the wood chest, 0 is the back of the turtle) (this is the view from the back of the field

b x 0 x x
x s x x w
http://pastebin.com/HhuPG1pX

I can tell you're a bit new. For Turtle programs, you should post them here. If you have HTTP API enabled, you can use the Pastebin program implemented in CC and upload the program by using "pastebin put <filename>" then put the link here, instead of pasting all the code here.

You're right, i am new. Though i can't seem to find how to delete/replace this post. I don't want to have double post, I'll try to edit this one so the program is in the pastebin folder though. Thanks for the lesson.

Can i replace the threat myself?