send and receive file over a network

Question

Recently i downloaded source code which is created by Th mok(Peer-to-Peer Chat program). The problem with this program is it can't connect to other pc to chat or send files. whenever it trys to connect it shows remote is close.Please help me to overcome this problem, if u have any other program which can tranfer files and receive please be kind to help me, it will be really helpful for me. (Student)