Automatic show more and add more records to pdf

I have 2 jobs for my social networking site - easy job if you have done this before: (1) I need an automatic 'show more' system on our messages with approximately 20 feeds shown, then 20 more shown, then 20 more shown as the person scrolls down the page etc - it must be automatic (e.g., something like [login to view URL]); (2) we are currently able to open a print preview of a message with pdf preview (so they can print their message)... however this only allows 1 database record to show, we need to be able to add more records to this pdf; Needs to be completed asap