family case

hi good afternoon... i want to consult my case... i am married with a 7 year old son, i am based in abu dhabi and my son is with my mother back in the Philippines. my husband and I are separated for almost 4 years now(although not legally, haven't filed an annulment yet). My husband has not been supporting my son financially since we separated. He is based in Qatar now as he is working there. I have decided to ask for financial support from him as i realized it's my son's right and his obligation. His family gets the chance to take my son in their house over the weekends regularly. Should i do this legally, i mean, be it in writing or just speak to him about it. I haven't been talking to him since we ended. please advice me how i should handle this matter. thanks...

talk to him first then formalize your agreement in writing. here is a good resource from australia. i wish it were as specific in the philippines:

http://www.csa.gov.au/parentsandcarers/limitedAgreements.aspx