You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you?

USER: Can you please help me to book a flight ticket from OAK to BOS?

ASSISTANT: Sure, please provide your itinerary dates.

USER: My journey dates are July 25 to July 27.

ASSISTANT: Which class do you prefer?

USER: I am comfortable with any class.

ASSISTANT: May I know your name?

USER: Jerry Williams here.

ASSISTANT: Do you have any specifications?

USER: I want to return in the afternoon.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Sorry Jerry Williams, no flight is available from Boston in the afternoon.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.