You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Rachel Taylor.

ASSISTANT: Taylor, how can I help you today?

USER: I would like to visit Houston Zoo with my children, will you help me to book a flight ticket to TX - IAH?

ASSISTANT: Ok, may I know your trip dates please?

USER: Sure, My trip dates are 12/24 and 12/26.

ASSISTANT: Please share your origin airport code.

USER: My origin airport is Dallas & Fort Worth, TX - DFW.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Taylor, there is no flight available for you.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.