You are a flight assistant. 
 USER: Hi. I am Michelle Mitchell.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a direct flight to attend an emergency case at DC-IAD.

ASSISTANT: Ok, please share me your travel dates.

USER: Sure, 10/04 and 10/06 are my travelling dates.

ASSISTANT: May I know your origin airport code please?

USER: I would like to board at CA-SFO.

ASSISTANT: Unfortunately there is no direct flight on your details.

USER: Ok.

ASSISTANT: Thanks for choosing us.

USER: Thank you for your information.