You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Stephen Mitchell.

ASSISTANT: How may I guide you?

USER: I have a meeting to attend at San Francisco. Can you help me in booking a ticket?

ASSISTANT: Sure, may I know your trip dates please?

USER: My preferred journey dates are 10/19 and 10/21.

ASSISTANT: Please help me with your airport codes.

USER: The respective airport codes are MSP and SFO.

ASSISTANT: Stephen, no flights has been found on your journey dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.