My question involves labor and employment law for the state of: New Jersey

I am on h1b. I joined my employer around 4 months and working in client site. Now got a full time job and would like to switch. However somehow my employer got to know that I may transfer and holding my Pay Stub. And they are threatening that they are going to sue me. In my contract agreement, its mentioned that they have right to claim "any liquidated damages but not penalty". And there is no where they mentioned about the amount that they would be claiming. My question is usually in this type case, how much do they claim in case ifI end in transferring the H!B? The contract is about 2 years.