My son just decided that he would prefer to go live with his father in Fl (I live in NY) so we now share joint custody. The question is what is my legal responsibility to pay his child support? He pertitioned the curt for custody and I agreed but only to joint custody.

Welcome to AMHD. Is there a custody/support order in place? About.com: http://dor.myflorida.com/dor/childsupport/guidlines.html (http://singleparents.about.com/gi/dynamic/offsite.htm?zi=1/XJ&sdn=singleparents&cdn=parenting&tm=7&gps=126_191_1276_865&f=00&tt=13&bt=1&bts=1&zu=http%3A//dor.myflorida.com/dor/childsupport/guidlines.html)