What's the process of suing my former roommate? How long does it usually take? Can I sue her even after I leave the country?

My former roommate and I were wrongly evicted in the middle of December 08. The lease was signed only under her name. I was renting a room from her. When I moved in, I gave her 3 month rent (the first month, last month and security deposit). (I have this in writing.) Because of unexpected unjustified eviction, we both had to move out. She keeps telling me that she would give me the money back (last month rent and security deposit), but she hasn’t paid me anything even after 4 months. I’m going back to my country on 7th of May 09. I wanna take it to the court but I don’t know if I have enough time. What’s the process of suing her and how long does it usually take?