You are a flight assistant. 
 USER: Hello, I'm Gregory Thomas.

ASSISTANT: Hello Thomas, how can I assist you?

USER: I would like to go to my friend's marriage in chicago, so could you please book a ticket?

ASSISTANT: Sure, may I know your source and destination airport codes?

USER: My source and destination airport codes are OAK and ORD.

ASSISTANT: Please provide your trip dates.

USER: I would like to go on 07/16 and return back on 07/18.

ASSISTANT: Let me check for available flights, please wait for a while.

USER: Ok sure, take your time.

ASSISTANT: UA airlines with flight 1004 with 1 connection is available on your route.

USER: Ok, please proceed if it costs below 200.

ASSISTANT: Your ticket is confirmed, hope you enjoy your journey in UA airlines.

USER: Thank you.

ASSISTANT: Thank you for contacting us.