A pupil at a Nottingham school had his drama class interrupted when he was sent a stripagram for his birthday.It is believed the parents of the pupil at Arnold Hill School booked a singing telegram as a 16th birthday surprise, but got the stripagram by mistake.The stripper, who was dressed as a policewoman, performed her act in front of the Year 11 class.Education chiefs are investigating the "highly inappropriate" incident which took place on Tuesday.A spokeswoman for Nottinghamshire County Council said no-one had been suspended and the police had not been called.