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

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, kindly mention your travel dates?

USER: I want to travel on 08/11, and need to catch return flight on 08/13.

ASSISTANT: Can you please provide me your airport codes?

USER: I need to leave from my nearest airport IAH to reach AUS.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no flights found with your requirement.

USER: Ok, no issues.

ASSISTANT: Thanks for reaching us.

USER: Thanks for the information.