Please rate my first script, basement script

I made a script to make me a basement, and thought i would share it with you.

It makes a basement, and you can deside the dimensions your self, tho it will be a square, it will place a lamp in the middle, and change the walls, floor and roof.

Here it is: http://pastebin.com/B4xxVfcS

Sry, here are some pics of it when it's done

some screen shots would be nice :D/>

does this dig straight down or make stairs? or does it just clear a room based on the dimensions you input?

It excavates from top top bottom, and it's made so you place it in the first right conor in the floor of the room, then it does the rest :)/>

What are the default dimensions?