Where it says "comment" click. Write your question and put the "@" symbol with the username next to it. Like this "@username". Then hit send!

Add the@with their screen name ask your question hit send

The other posters are correct! :) You ask questions via the individual item listing comment section. When asking your question, first type the person's username in the comment box, being sure to put@ in front of it -- this "tags" the person in your comment so they're sure to get it. Whether they comment back is another issue -- you'll get a lot of "i don't know lol" comments. :\ But I do hope you get the info. You're looking for!

You have to ask via the comments box