Dan and Elaine were divorced in 1999. The divorce decree ordered Dan to pay $350 a month in child support for their daughter, which he has faithfully paid. A year later, Elaine goes to an attorney to seek help in obtaining an increase in child support to $500 a month. Is there any policy reason against the attorney taking this case for a fee of 20 percent of everything a court orders Dan to pay above $350 a month?