You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Brandon Parker want to visit Houston zoo, can you book a ticket within the fare of 200?

ASSISTANT: Sure, I will help you in booking your ticket.

USER: Ok.

ASSISTANT: Can you please provide your travelling dates?

USER: Yes, my travelling dates are 12/24 and 12/26.

ASSISTANT: Ok, may I know your travelling airport codes?

USER: Sure, I want to fly from SEA to IAH.

ASSISTANT: Ok, please wait a moment to check the availability of flights.

USER: Sure.

ASSISTANT: Sorry, there are no flights available on these dates.

USER: That's fine, thank you for the information.

ASSISTANT: Thank you for choosing our services.