Hollywood funnyman Jack Black is terrified of his impending fatherhood because he's racked by doubts he'll be a good parent. The KING KONG star and musician wife Tanya Haden are expecting a baby any day and have already tentatively named him SAMUEL. But Black is worried his troubled childhood - in which his parents split in a messy divorce when he was just 10 - could affect his parenting skills. He says, "It's scary. I haven't read any books on the subject. What if I mess him up? "What scares me is that someone's going to have to give him discipline, and what am I going to do? "I can't imagine myself in that role because I've been so undisciplined in my life and it's served me well. That might fall on Mama's (Haden's) shoulders." Black and Haden eloped in March (06). The couple first met while they were attending a private performing arts high school in Santa Monica, California, but were not romantically involved.