Employment Authorization
U.S. employers must check to make sure all employees, regardless of citizenship ... If you are not a citizen or a lawful permanent resident, you may need to apply ...
http://www.uscis.gov/portal/site/uscis/menuitem.eb1d4c2a3e5b9ac89243c6a7543f6d1a/?vgnextoid=1847c9ee2f82b010VgnVCM10000045f3d6a1RCRD&vgnextchannel=1847c9ee2f82b010VgnVCM10000045f3d6a1RCRD