You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I assist you?

USER: I am Brenda Adams, can you help me to book a flight to IAD?

ASSISTANT: Sure, May I know the source code?

USER: My preferred source airport code is CLT.

ASSISTANT: Please help me with your travel dates.

USER: My travelling dates are 12/25 and 12/27.

ASSISTANT: Please wait a minute.

USER: Ok.

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

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for opting us.