I moved in with my roommate in Jan of 2008. In Jan of 2010 she decided to quit her job, move out and go back to school leaving me to handle bills that we were both responsible for. Due to a pay cut I couldn't handle all the bills on my own and I eventually moved with a friend. After explaining the situation to the landlord and trying to get in contact with my former roommate, this past Tuesday(3 months later) I was taken to court and ordered by the judge to pay the full amount including late fees for our house. I had paperwork to show that I had not entered into this lease alone and didn't have the full amount to pay but would be willing to pay my half of fees. But I was still ordered to pay in full. Are there any laws I can look up about this matter or have any ideas on how to handle this situation?

Go to Small Claims Court, sue her, present proof that you were ordered to pay (and did pay) "her" share as well as yours.