Ajax: AutoCompleteExtender version

I have been catching up on a project recently. This project needs to use the automatic completion function. I have never touched asp.net Ajax before, so I have to make up for it. Now I have gained a little bit, instead, let's talk about a problem I encountered recently. This problem has long existed, but no one answered it clearly.

When I use AutoCompleteExtender in the project, I see that many people useCompletionListCssClass= "Style of the prompt list"
CompletionListItemCssClass= "Style of unspecified items"CompletionListHighlightedItemCssClass= "Style of the selected item", but I cannot use these three attributes after I add them to the code. I found them online for a long time. They said they were a version problem, but I didn't explain how to solve it. I used VS2005.

Open http://www.asp.net/ajax/, single-click toolkitand Go To The Asp.net ajax control toolkit page. This page provides a detailed description of the control toolkit. The last part of the right part of the page is:

Note:This Septemeber 2009 release:Toolkit version 3.0.30930IsOnlyFor users who are building on top. NET Framework 3.5 using Visual Studio 2008.
If you are using. NET Framework 2.0 and Visual Studio 2005Then you shoshould use the earlierToolkit version 1.0.20229At CodePlex.

Click CodePlex to download and install it. Previously installed files do not need to be uninstalled (as if not affected)

Thank you.