The question has been answered many times before. @isoutamo already pointed you to a trove of resources for writing such search. If you don't understand some specifics about any of those things said in other threads wiith solutions don't hesitate to ask for explanation. But don't expect people to jump in and do your job for you - the issue is well known and has well known method of dealing with, explained many times. So all you need is to dig into those resources, read the solutions provided there and try to construct your own. If you encounter some obstacles along the way, ask away. ... View more