Why ASP.NET AJAX UpdatePanels are dangerous
AJAX, ASP.NET, Performance By Dave Ward on July 11th, 2007If you’re like me, it’s hard to resist the lure of tossing a half dozen UpdatePanels on every page and reveling in AJAX goodness. The UpdatePanel makes AJAX trivially easy for anyone to implement, even without knowledge of what’s actually going on behind the scenes.
Unfortunately, that very lack of transparency regarding the mechanics of the client/server exchange makes it all too easy to shoot yourself (or your application) in the foot. Let me give you an example that you’re probably familiar with by now, and thoroughly sick of seeing:

When you have a name as common as mine, you run across the entire gamut of schemes to deal with username availability in membership systems. By availability, of course I mean denial and rejection. Out of all of the ways that I’ve had “Dave” rejected, inline AJAX verification is definitely the least annoying. Wanting to be less-annoying myself, I’ve added the same functionality to my ASP.NET AJAX sites. Let me show you how I did it.
Just a quick Highslide update.
Your wishes are my command. Highslide JS .NET now includes support for captioning. The captions can be specified using the Caption property of each HighslideImage control, and can be easily styled using CSS.