You are a flight assistant. 
 USER: Hello, I am Ruth Evans.

ASSISTANT: Hello, how may I help you at this moment?

USER: I would like to go to a beach in San Francisco, so could you please book a ticket for me?

ASSISTANT: Can I have your dates of your trip?

USER: I would like to go on 12/22 and return back on 12/24.

ASSISTANT: Please share your nearest airport codes. Please stay online for a moment.

USER: My source and destination airport codes are PHL and SFO.

ASSISTANT: Noted.

USER: Ok, ensure it is a single connecting flight.

ASSISTANT: There is a single connection flight available with UA airlines, shall I book it?

USER: Ok, please proceed for further. If it costs you below 500.

ASSISTANT: Your ticket is confirmed with flight whose service number is 1000.

USER: Thank you.

ASSISTANT: Welcome. Thank you for reaching us.

USER: Welcome.