I am a green card holder, and it was an employment based one... my agency was my sponsor. I came over on a 21-month contract, and at my green card interview I was asked whether I intended to take up post on my arrival, and to promise to start the job when I arrived in the US. I did this, and I have now been here 4 months. I want to break my contract and get another job on the other side of the country. Am I allowed to do this or will I be breaking a rule and jeopardizing my green card if I leave? If I have a green card am I now free to do whatever I want?