patent issue, help need.

I am working for a small private research company. My boss will submit a US patent application based on my own research results and my independent research project. The protected subject would have multimillion US dollars sale each year in America market. However, I saw he would be the only inventor in this patent application. I do not think it is fair for me. The research project is proposed by him but accomplished it by my hard work. In addition, my employment agreement shows that all research results belong to employer only.

I would like to argue with my boss, but I think it is impossible to persuade him to add me as co-inventor. If I seek litigation, what is the chance that I can win?

Thanks for any comment.