Designing a similar feature in Yahoo Article Detail Page

I would like to implement a feature similar to Yahoo's articles detail page. When you click on an article in Yahoo's homepage, the article's page seems to be opened in probably a new DIV on top of the home page.

And there is a close(X) link at the top right that you can click to close the DIV and go back to the home page.

When the article's page is opened, you see that the background/homepage becomes white as if the homepage is not there. But when a user clicks on the (X) link, the homepage comes back and the article is closed.

I want to implement similar feature myself.

I have googled but could not find any tutorials about this feature.

Can someone point me to the right direction or a tutorial that can help me to implement such feature.

Thanks.