Disparate systems communicate with each other using protocols. A protocol is a set of rules that governs the transmission of data between two independent systems. If you're familiar with protocols, then you will know that most are composed of simple, plain text commands. In this article Mitchell shows us how to create a protocol and implement it as a server using Visual Basic and Winsock.
Building A Document Request Protocol Part 1/2 - Our VB App in action (Page 6 of 7 )
Throughout the last two pages, you would've noticed a lot of calls to the lstDetails.AddItem function. This function accepts a string, and adds the details of any data that is either retrieved or sent to the client to the listDetails list control.
Here are a couple of screen shots of our VB app in action. Obviously you’ll need to code up a client app before our VB app will function properly (and we will do that using PHP in part two of this article), but I just thought I would show you how it looks anyway:
PHP 
Building A Document Request Protocol Part 2/2
