Income tax return

by ms. murphy
(Texas)

Hi, my husband and I have been separated for almost 5months. Before the separation I was a stay at home mom to our 4yr old. I worked part-time for a very short period during the holiday season. I didn't make enough to file my own tax return. My question is: will I be able to get a portion of my husbands tax return if he files and claims my son. He is also behind in arrears. I just received my first payment the other day and the first payment was due on Dec.1,2010. I am the custodial parent and am aware that he IS NOT suppose to claim my son! How does this work in a situation like this?