I have make an application as trial period .In this application contain .afl file it Contain my functionality and this file make as trial period i am beginner in this so please help me....this .afl file is make in c++....plz help..

forget about it.
But read the file format specifications, see if there's a defined API for it that can give you the data you need, then find a way to enforce the restrictions.
And THEN try to ensure that it's secure so people can't just hack their way around it (which is where you'd best start forgetting about it, as a beginner).