You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me with booking a flight ticket from OAK to SFO to meet my friends.

ASSISTANT: Yes, can you tell me your dates of travel?

USER: My travelling dates are Mar 18 and Mar 20.

ASSISTANT: Do you have any other preferences?

USER: Yes, I want to return in the evening.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights found on your requested criteria.

USER: No worries, thank you for the information.

ASSISTANT: Can I know your name?

USER: I am Justin Young.

ASSISTANT: Thank you for contacting us.