You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Charles Walker. I have a business meeting in San Francisco. Can you help me to book a flight ticket?

ASSISTANT: Sure, may I know your airport codes please?

USER: My travelling airport codes are from PHL to SFO.

ASSISTANT: On which dates you like to travel?

USER: My travelling dates are from 07/23 till 07/25.

ASSISTANT: There is flight with single connection, can I proceed for booking?

USER: Ok, please proceed for booking.

ASSISTANT: Your booking is done in 1012.

USER: Thank you for booking.

ASSISTANT: Thank you for choosing us.

USER: Welcome.