How can i create scrap like feature in my site?

Hello can anybody give me a brief idea of how to create a scrap like feature in my site? Paging should be enabled and in each row reply button should be present. Clicking it another box should get opened with submit and cancel button at the bottom(I really don't know how to accomplish this :( ). If user clicks submit button then using ajax the scrap should be sent to database. Any ideas or snippets of code are most welcome!
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