I have an application this is already license but in this application use my functionality put custom .afl file this file make in c++ make this .afl file as trial period.So how to make this .afl file as 7 day trial period.....i am beginner so plz help me...

Have no idea what an .afi file is, but to make a program work only during trial period the program needs to check a computer clock time/date against the install time/date. It's too easy for people to just change the computer's clock in order to circumvent the trial period so the program should access a clock from some other computer, such as a web server computer over the internet.