Thank you very much for your answers! I guess I will have to hire a profession to conduct an investigation in ex's financial assets first before I can do anything. I just feel so bad luck for having such a horrible and irresponsible ex. My kids are still very young. It is so heartbroken for me to think that I have to significantly sever my kids' financial needs. I really wish that the Court could help my kids get justice.
Once again thank you very much. Have a happy New Year!