Three male programmers were in the bathroom standing at the urinals.

 The first programmer finishes, walks over to the sink to wash his  hands. He then proceeds to dry his hands very carefully. He uses paper  towel after paper towel and ensures that every single spot of water on  his hands is dried.

 Turning to the other two, he says, "At Windows, we are trained to be extremely thorough."

 The second programmer finishes his task at the urinal and he proceeds to wash his  hands. He uses a single paper towel and makes sure that he dries his  hands using every available portion of the paper towel.

 He  turns and says, "At Macintosh not only are we trained to be extremely  thorough but we are also trained to be extremely efficient."

 The third programmer finished and walks straight for the door, shouting over his shoulder.

 "At RedHat, we don`t PISS on our hands."

Teacher: How do functions break up???

Jerry: They stop calling each other.