What are the masses of the two stars (given the information provided)? If anyone would at least be willing to point me in the direction of finding the answer, or help me solve it I'd appreciate it. I don't know how to go about this, and need to know how to solve this on my own (plus I need the answer for a homework assignment, but just an answer isn't gonna help).

Question:

The spectral lines of two stars in a particular eclipsing binary system shift back and forth with a period of 10 months. The lines of both stars shift by equal amounts, and the amount of the Doppler shift indicates that each star has an orbital speed of $~8.0\cdot 10^4~ \mbox{m}/\mbox{s}.$ 
What are the masses of the two stars? Assume that each of the two stars traces a circular orbit around their center of mass.
You need to use the generalized (a la Newton) form of Kepler's third law; see here.