im also working on chat server program to send messages or files to client.....at this time its working on LAN .but now i want it to extend to work on WAN so that i can send message to any other PC having my client program....just like another messanger(like Yahoo messanger)....if its possible than how?? in my chat server program im using WINSOCK and then i need to enter at the client side. IP of the Server PC to connect the client with the server then i can send messages and files . its only working on LAN .i want it to work on WAN. plzzzz help me ??