Php JQuery Live Update

I have a MySQL database I'm pulling content from and I want to create a feed like twitter displaying the content "live". I want the page to load only 10 results and as you scroll down the page I want it to start loading more results, 5 results at a time. Also as new content is added to the database I want a button to appear over the top of the first content giving users the option to load new content. When they click the button it should load more content without refreshing the page. I want it written in php and ajax/jquery. I will configure it with my own content so just send an example code over with the structure once completed.