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

ASSISTANT: Hello, How can I assist you?

USER: I want to book a flight ticket to Washington to visit white house , please help me with a connecting flight.

ASSISTANT: Sure, May I know the journey codes?

USER: I want to fly from OAK to IAD.

ASSISTANT: Please help me with your travel dates.

USER: My travelling dates are from 12/10 to 12/12.

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

USER: No issues. Thank you.

ASSISTANT: Thank you for opting us.