How Google determine the Site Links?

Hi All,
I want to know about site links which appear in the search engine when you search some keyword then the top site in the results have some extra links below its title,description, called i think site links. How Google take those links and why only those why not other links showed up there from that site.

Thank You

It is auto generated result on behalf of Google. It is shown when that site or portal is relevant to Key phrase which is searched by user. If your site meets the guidelines of Google then it shown.

As Terence says, it’s all done automatically. Whether Google includes ‘site links’ for your site will depend on how well structured your site is (ie, if it can easily work out which pages are relevant to be included), and how popular your site is. More popular sites are more likely to get site links.

Thank You Terencelewis and Stevie.
So that mean there is no way we can identify which site links will appear below the site, it is totally automated by. I have asked this because i am thinking weather it is possible or not to put our own wish list of links there so that they show up every time when search goes.

As far as I am aware, there’s no way to influence the site links at all, other than by giving prominence to particular pages within your site, to try to direct traffic through those pages and promote them within search engines.

Ok, Thank You so much Stevie, any how i have searched it too, but can’t find it.
Thank You once again.

SEOmoz suggest:

Potential Factors that Create Sitelinks:

* Domain Authority & Trust (based primarily on links, possibly with some aging factors as well)
* Branded Search Query Volume
* Existence of Multiple High PageRank, Highly Searched-for Internal Pages
* Significant Domain Traffic (as measured through toolbar users or other data)
* Popularity of Brand/Domain Mentions on Pages Across the WWW
* Link Growth Trends (if the site receives a regular influx of new links vs. a very spiky, inconsistent link growth pattern)

I see it on big brands mainly.