http://www.catb.org/~esr/faqs/smart-...html#writewell
Try expressing your thoughts so it can't be sent as an SMS message.

You have choosen a nice user id. In C++ one can code stuff from mini calculator to satellite , so you need to choose the topic for your project assignment.

*waves his hand like a Jedi*
You want to code an open source active directory clone.....

You have any idea what are you asking?
We don't know you, nor your ability, nor that how much time you have, not how much brains you have. We know nothing of you then how can we tell what is a "mini" project for you.
Mini can be a Hello World program or mini can be a writing a C compiler.

thanks....i got nice definition....mini project based on "multiplex booking system online"....it will fine or not?

You have to code that. So its completely your decision. By the way.... if "online" mean through the internet, then it will be a nice one. You will have to learn something about sockets and protocols.