You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Christine Green.

ASSISTANT: How can I assist you today?

USER: I am planning to book a ticket from SFO. Can you help me out?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: I would like to travel on 06/17 and return back on 06/19.

ASSISTANT: Please mention your destination airport code that you want to travel.

USER: My destination code is LGA.

ASSISTANT: Please give me a moment.

USER: Sure, I will wait for your reply.

ASSISTANT: Thanks for waiting, there is no flights available under your preferable details.

USER: That's fine. Thank you for your service.

ASSISTANT: Welcome, have a great date. Welcome, have a great day.