Stack Implementation
Here are some things that may help you improve your code.

Throw errors rather than printing error messages

The user of your code may be creating a GUI with no command line available and will not appreciate having your code printing instead of indicating an error to the calling code.  The two ways that C++ programs generally signal an error are either by throwing an exception (if the circumstance really is exceptional) or by returning a value that indicates an error. 

Use consistent formatting

The code as posted has inconsistent indentation which makes it hard to read and understand. Pick a style and apply it consistently. 

Consider adding functionality

Since this is a fixed-size rather than a dynamically sized stack, it would make sense to either allow the user to specify that size (as perhaps with a default parameter for the constructor) and to query it.  Also, consider adding functions such as isFull() and isEmpty().