County music singer Lynn Anderson's battle with her former husband, Harold "Spook" Stream, for custody of their two children has turned ugly with allegations of drug abuse. The custody fight is over the couple's 11-year-old son and 9-year-old daughter. During a circuit court hearing Friday in Nashville, Tenn., Anderson and Stream both testified that although they once used cocaine, they are now drug-free and challenged each other to take tests to prove it. "I'll be glad to take a blood test or whatever you'd like," said Anderson to Stream's attorney. "I think we're beating a dead horse here. I think both of us have stopped doing anything like that some time ago."