LAN Chat system is a complete client/server chat solution, independent chat system(it does not depend on any product of communication and chat). It has a Nice and clear user interface Using Socket Programming in Visual Basic 6.0. It can accept multiple connections.

There are also a few commands built in which include retrieving server date, time and uptime and can also be remotely shutdown. Both client and server use Windows Sockets for the purpose of connecting and sending lines of text between themselves. LAN Chat system application is a GUI interface for Net Send which allows identity spoofing, buddy management, blocking messages, and searching users in a domain. This application makes it easy to find people on a LAN and communicate with them easily without being online and makes net messages easier to read. The concepts of a chat-enabled application, like creating and entering chat rooms, sending and receiving chat messages, and management of user profiles, are abstracted by Prism Server and made available through simple properties, methods, and events.

Server features: messages history, statistic reports, easy managing of users and connections.

Client features: Instant messages, multiuser conversations, file transfer with multispeed option (with 2-3 clicks send the same file to more contacts), offline messages, auto-save conversation, local timestamps, contact groups (with more options, like “Invite group to conversation”), custom statuses, personalized alerts , print/print preview, send conversation with mail and more. Perfect communication for professional teams (programmers, hotel staff, science labs etc.). Compliant with all types of TCP/IP networks (LAN, WAN etc.).

Working Principle:

Following is how the application starts and how it works:

1. As soon as the application is started, the main thread is spawned by the system.
2. The main thread then spawns a thread which keeps listening on a given port.
3. As soon as there is any connection request from a client, a connection is established. After the connection gets established, another thread is spawned to open a dialog box for chatting with clients.
4. For every connection to a client, a new thread is spawned. Hence, if there are three clients connected to the server, then the total active threads will be five, one main thread, one thread for listening, and one each for chatting with the connected clients.

Now, let’s look at what each thread, that corresponds to a client connect, does:

1. Calls the asynchronous Begin Receive method. A callback method is passed a parameter. This callback method is called when any data is received on that socket.
2. When data is received on a socket, the data is read and displayed on the rich text box of the chat dialog. However, if a Socket Exception is raised, then the connection is closed, as this means that the client has asked to close the connection.
3. When the Send button is clicked, data is sent to client.

Hardware and Software Requirements :

• Minimum 2 PC’s
• Minimum 40 GB Hard Disk
• 500 MB RAM
• Windows XP Service pack 2
• LAN Connection
• Visual Basic 6.0