A school teacher injured his back and had to wear a plaster cast around the upper part of his body. He wore it under his shirt and it was not noticeable at all. On the first day of the term, still with the cast under his shirt, he found himself assigned to the toughest class in the school.
Walking confidently into the rowdy classroom, he opened the window as wide as possible and then busied himself with desk work. The classroom became a bit unruly and he admonished them. This happened several times. While working at his desk, the strong breeze from the window made his tie flap annoyingly. He kept rearranging and rearranging the tie as the class become more and more unmanageable.
Finally, becoming disgusted with the wayward tie, he stood up and took a big stapler off his desk and stapled the tie to his chest in several places.
Discipline was not a problem from that day forth.
The students must have dumbstruck, by seeing the action of the teacher.