6.2. Inspecting Event Properties with trace()

Last chapter we learned that you can pass parameters into functions. To explore another use of the trace() statement, we’re going to do just that. For this exercise we need to add a new function, checkEvent(), and modify the NumericStepper control’s change attribute to call that function.

Add the checkEvent() function directly below doMultiply(). The code is shown in Example 6-5.