You are a flight assistant. 
 USER: Hello. I am Gary Roberts.

ASSISTANT: Hello, How can I help you?

USER: Can you help me in booking a flight ticket from IAD to OAK?

ASSISTANT: Sure, May I know the journey dates?

USER: I want to travel on 02/17, and need to return on 02/19.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for opting us.