You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I help you today?

USER: Please, reserve me a round trip flight ticket to Houston, TX-IAH. Can you help me with book a flight ticket?

ASSISTANT: Sure, can you please share your travel dates?

USER: My travel dates are 04/25 and 04/27.

ASSISTANT: May I have your name please?

USER: Mary Rodriguez here.

ASSISTANT: Sorry to say that, no flights are available on your requested dates.

USER: No problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.