Using timer interrupts in a library

"FIFOClass" is the name of the class I want to create an instance of

Here is how I normally create an instance:FIFOClass FIFO; Is that the proper syntax to create an instance? The compiler complains "error: 'FIFOClass' does not name a type".

In the library .h file I #include d the .h file for the class, like this:#include <FIFO.h>