Arduino starter kit problem with Project 12 (piezo) -knock lock

Projects General Guidance
1

For some reason my piezo does not even run the code for line 39 to 53 in the starter kit book. I even added numberOfKnocks = 0; and tried to rearrange the piezo in different ways from this link: project 12 / knock lock: problem reading the input value of piezo - The Arduino Starter Kit - Arduino Forum
All I get in the serial monitor is
The box is unlocked!
The box is locked!
The box is locked!
The box is locked!
The box is locked!
The box is locked!
The box is locked!

I'm sure its the piezo but I don't know what the problem is.

2

Why don't you use this tutorial instead so you don't have to deal with the box locked/unlocked problem
http://playground.arduino.cc/Code/ToneAC

3

Not exactly the correct substitution but Thank you!!