Exception handling plays an important part of application management and user experience. If implemented correctly it can make maintenance easier and bring the user experience to a higher level. If not, it can be a disaster. How many times have you seen the error message that doesn't make any sense or at least provides some valuable information, or even better - how many times have you seen the famous error screen with exception message and a complete stack trace on yellow background? Too many times, I would say. This is why, among other things, some of my colleagues were very interested in exception handling techniques and best practices. The goal of this article is to provide an overview of what exception handling is from the user perspective and the perspective of people who maintain the application, and to show the best practices of how to implement useful error handling in ASP.NET web applications. This article is related to my previous articles CSS Message Boxes for different message types and Create MessageBox user control using ASP.NET and CSS since this two articles describes how to show user-friendly messages. 1. What information should be presented to the user?Like I mentioned before, meaningless error messages will confuse users. Not having any error message and allowing the application to stop will make them wish they never clicked on the link that pointed to your website. :) Messages like "An error occurred" or "System.InvalidOperationException: The ConnectionString property has not been initialized" mean nothing to the end user. One doesn't know what has happened exactly, has the information been saved, and what should one do next. Read more: Janko at warp speed