Bernie, who was a school teacher by profession, injured his spine in an accident and had to wear a plaster cast around the upper part of his body.
He wore a cotton shirt over it and it was not evident at all.
As the new term began, he was assigned to a senior class with the rowdiest students in school.
Walking confidently into the classroom, with the cast still under his shirt, Bernie opened the window wide and then got busy with some desk work.
There was a strong breeze that made his tie flap, so Bernie simply picked up the desk stapler and stapled the tie to his chest.
The whole class of trouble-makers went silent.
Bernie had no problems with discipline in that term.