Developing applications that support multiple users requires much more defensive coding techniques than single-user, desktop applications. If the possibility exists that two or more individual users will be working with the same piece of data at the same time, your code must be written to prevent concurrency problems. In this article, I've shown how Web applications can use the so-called timestamping technique to prevent lost update problems. I like using this technique because even if it requires a little bit of coding, its much more flexible and produces a better result than the other techniques I have tried. I encourage you to form your own opinion by downloading the sample application, opening it up in the Visual Basic IDE, and stepping through the source code to see how everything works together.