I am bussy developing a web application using delphi, i need my application to use a barcode scanner for filtering, please give me an idea on how to go about achieving that.
Use a commercial library. It is worth the $$.
There are also some good free ones.
You can google around for more if you like. Be aware that not all scanners are equal. Know what equipment you intend to target, and select a library that can handle it.