How To Develop/Adjust ASP.NET User Controls For Multiple Instances Support
When developing ASP.NET user controls you should keep in mind whether they need to support multiple instances feature or not. In other words, you should decide if more than one instance of your user control could be added on the same page. Why do you need to make up your mind on this? Because when clicking a button on one instance you may end up applying its logic on all instances or at least on another improper instance.
This article is a walkthrough which takes you from the early steps of writing the code up to its final form.