This morning, I had the chance to play around with another ASP.NET AJAX control: the CascadingDropDown control. Like the name implies, it's a nifty little AJAX-enabled control that dynamically enables and populates a DropDownList based on the value selected in a previous list. Kinda like the coding version of those old skool "Choose Your Own Adventure" books.
You've seen this kind of thing in action plenty of times, I'm sure. Remember the last time you filled out a registration form that had you pick a country, then you suddenly had a "State/Province" list that only included regions within that country? Well, this is Microsoft's implementation. Check it out: http://www.asp.net/AJAX/AjaxControlToolkit/Samples/CascadingDropDown/CascadingDropDown.aspx
As with most of the ASP.NET AJAX stuff, there's also a great "How Do I..." video (http://www.asp.net/learn/ajax-videos/video-77.aspx) from Joe Stagner (http://www.joeon.net). Thing is, though, that the video uses an XML file for its data source. Not real helpful for me, seeing that my data was coming from an actual SQL database.


