Content Page Navigation by AJAX

Question

Hi there,

I want to know how to navigate between content pages by loading them only and not the full master page template ?

Example: If I have MasterPage.master, Default.aspx and Default2.aspx, and there is a link for Default2.aspx in Default.aspx,

when I click that link, I dont want the full page included in the master page to load, but only the content part by using AJAX.