Query Pages library using Javascript client object model

Hi,

I have a publishing site. In the pages library, i have column called "Category". The options in category are "News", "General".

When a new page is created , the users select the category and then add contents to page. I want to fetch the published pages from "Pages" library which are of category "News" using Javascript client object model.

I have checked this: http://snippetfire.com/s/33/net/programmatically-read-publishing-page-sharepoint

But not sure, how to do it in Javascript client object model.

How to achieve this?

Thanks