It is in the OnTimer function that things begin to get interesting. Here, you still see the
code for handling the clock timer event. To add the functionality for the counter timer,
you need to determine which timer has triggered this function. The only argument to the
OnTimer function just happens to be the timer ID. You can use this ID in a switch statement
to determine which timer has called this function and to control which set of code
is executed. The clock timer code is still the same as it was in Listing 4.2. The counter
timer code is placed into its spot in the switch statement, incrementing the counter and
then updating the m_sCount variable with the new value. You can compile and run your
application at this point, and you can specify a timer interval and start the timer running,
as in Figure 4.6