You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I would like to book a ticket from PHL to SFO. Could you book a ticket?

ASSISTANT: Can I have your journey dates?

USER: Departure is on Mar, 5 and return date is Mar, 7.

ASSISTANT: Do you need any connection limit?

USER: I would be comfortable with single stop over.

ASSISTANT: Do you need any other specifications?

USER: I prefer normal-cost airlines.

ASSISTANT: May I know your name?

USER: My name is Gary Mitchell.

ASSISTANT: There are no flights available on your routes.

USER: Thank you.

ASSISTANT: Thank you for choosing us.