A Milwaukee County judge will allow a 49-year-old sex offender to have limited visits with his son.  Doctors at Wisconsin Children’s Hospital say Stuart Yates’ nine-year-old son is seriously ill.  The judge’s ruling limits his visits to two hours, three times a week and a court-appointed guardian will supervise.  Security officers at the Milwaukee hospital escorted Yates out of the building four weeks ago after learning he was a registered sex offender.  The case which resulted in his name going on the sex offender list occurred 20 years ago.  His attorney says Yates did the time and has moved on. He was convicted of second-degree sexual assault of a child in 1998 and was sentenced to six months in jail. Yates said he didn’t know the victim’s age and that the incident happened at a house party where there were strippers.