Every website owner would like to see their web pages on top spots in the search engines but don't know how to do that. It has been found out that HTML markup used for navigation increases the page download time experienced by the visitor which in turn could drive away the visitor from your website and dent your search engine rankings. Here AJAX comes into the picture and it could be used for creating focused and faster loading web pages and hence improve your site's search engine ranking.

The separation of content on the web page from the navigational elements surrounding it results in a focused presentation of the content to search engines and reduces the loading time for users with slow internet speed as the actual content becomes visible to the user before the navigational elements get downloaded.

While redesigning the web page some basic form of navigation must remain on the web page in order to allow search engines and users who have taken a decision to disable JavaScript to navigate between the pages on the site. One could implement delayed loading of the navigational elements with inline frames or by using the XmlHttpRequest object implemented in most modern browsers. This object gives a tighter control over the loading process and the ability to detect and handle download errors. Get more details out here.