Okay...you see the quotation marks on the bottom right (next to the quote button). Click that on as many of the different posts as you want to respond to and then when you are ready to start typing, hit quote on the last one (BTW...when you click on the quote marks, they will turn red so you know that is now multi-quoted). Then you will see all the different posts quoted as you go to type. Use your preview button to see what it looks like if you get confused.