Terminology: What is this web gui action/type actually called

Terminology: What do you call this type of web gui feature?

I'm trying to research on a gui interaction where the user chooses an option, and the next set of options are loaded based on the previous.

I'm calling it cascading, but that doesn't seem to be right.

Example below:

User chooses company A

company A services load
user chooses service 1

serivce 1 loads, with only options company A wants

...cycle continues...

Silly question probably, but I am tired of getting all these search results that have nothing to do with what I'm after. Thanks in advance for any guidance.

If it matters, I'm thinking of using jquery f开发者_JS百科or this, with C#/asp.net backend. Chose not to include those in the topic tags as I didn't think the language would change the terminology.

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I think you're right with cascading if I understand you properly, ASP.Net/AJAX example here:

http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/CascadingDropDown/CascadingDropDown.aspx