You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Kenneth Hernandez here. I am a singer, I have to participate in a contest at Chicago. So please book my ticket from San Francisco.

ASSISTANT: Sure, please provide me your travel airport codes.

USER: My airport codes are SFO and ORD.

ASSISTANT: May I know your travel dates to search flight for you?

USER: My itinerary dates are 12/11 and 12/13.

ASSISTANT: Sorry, I could not find any flight with your details.

USER: It's ok, thank you for checking.

ASSISTANT: My pleasure.