Can someone help me here?

I'd like to use this accordion menu but as I'm a complete newbie to html I am having some major difficulty adding it to my project.

I'm getting all sorts of errors when I try:
Error updating JScript IntelliSense....
Elements occurring too few times
ddaccordion.js not found even though I've loaded it into the project.
The class of CssClass is not defined.
and quite a few others


Thought it would be a fairly simple thing to add but seems to be way out of my league. Does anyone have any tips or alternatives to achieve this type of accordion menu in Visual Studio?