After link click load different chunk

Is there a (javascript) method where I can change a chunk loaded into the template or the template itself by a frontend link?

I have an one page website and there needs to be two links.
One link loads chunk "1" and the other link loads chunk "2".
The URL i like to keep unchanged.

I will try one of these

http://www.jquery4u.com/function-demos/ajax/
http://jquerytools.org/demos/tabs/ajax.htm

Either:

1. Use ajax to load the chunk. The chunk can be via a MODx 'page' that only consists of that chunk. If you like jQuery use jQuery's load(). If you want to use normal non-library based javascript then you probably don't need anyone else to tell you what to do.

2. Include both chunks on your page but hide one and show it (and hide the other) with javascript manipulating the CSS display property.

(1) Is better for very large chunks. (2) is better for smaller chunks and will feel more responsive to the user.

-- Tim.

Not sure about SEO, guess sitemap is needed when using ajax and top:-999px; for jQ.