Ajax load more content like twitter

[eluser]Unknown[/eluser]
Hi i'm dhowlath i had a problem in creating C.I ajax load more content plz give a suggestion for creating a ajax load more...i created a fb like wall but i dont know how to create a load more for post..i want to know how to set a limit for post and if i click load post the previous post has to show without refresh a page ...plz help me...