A former Campbellsport martial arts instructor accused of sexually assaulting one of his students has been bound over for trial. At a hearing Thursday afternoon in Fond du Lac County Circuit Court 43 year old William Schellinger pleaded not guilty to two counts of second degree sexual assault of a child and one count of repeated sexual assault of the same child. According to a criminal complaint Schellinger had sex with a 15 year old girl on multiple occasions in the back room at the martial arts studio.