You are a flight assistant. 
 USER: Hello,. I am Brenda Hill.

ASSISTANT: Hello, how can I assist you?

USER: I need to visit Lyndon Baines Johnson library at Austin. Can you book me a flight ticket?

ASSISTANT: Sure, let me know your travelling dates?

USER: I want to travel on 02/06 and need to catch return flight on 02/08.

ASSISTANT: Please provide your airport codes.

USER: Source is from IAD and destination is to AUS.

ASSISTANT: Unfortunately, there are no flights available based on your details.

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

ASSISTANT: Thank you.