What is the conversation mainly about?

W: Excuse me. I’m looking for someone who can help me with the textbook reservation program.
M: Oh, well, I can do that. What do you need?
W: Okay.(4)Um, my friend told me that I could get used books if I order, I mean, preorder them now.
M: That’s right. Do you want to do that?
W: I think so, but I’m not sure how it works.
M: Actually, it’s fairly straightforward.(5-1)We have a short form for you to fill out. Do you know what you’re going to take next semester?
W: Yeah, I do.
M:(5 -2)And you have the course names and the schedule numbers for all your classes?
W: Un-huh.
M: Okay, then, just put that information down on the form and, uh, (5 - 3)make a checkmark in the boxes. And you said you were interested in used books, right?
W: Right."
M: So mark the box for used books, sign the form and bring it back to me.
W: Do I have to pay now?
M: No, you can pay when you pick up the books.
W: And when can I do that?
M:(6)The week before classes begin.
W: That’s good, but, um, what if I change my schedule? I mean, I don’t plan to but...
M: ...it happens. Don’t worry. If you change classes, (7)you can just bring the books back any time two weeks, from the first day of classes to get a full refund.