You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Brian Wilson. I want to book a flight ticket to take a part in flower festival which is going to held at TX-AUS. Can you help me?

ASSISTANT: Sure, May I know your travel dates?

USER: Sure. 10/13 and 10/15 are my travelling dates.

ASSISTANT: Please share me your depart airport code.

USER: I would like to start from TX-IAH.

ASSISTANT: There is no flight on your details.

USER: No issue. Thank you.

ASSISTANT: Thank you.