You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Catherine Martin.

ASSISTANT: How can I assist you at this moment?

USER: I am planning to have a round trip from Houston, can you please book me a ticket from IAH to HOU?

ASSISTANT: Sure, please provide me your journey dates.

USER: My preferable journey dates are from 04/21 to 04/23.

ASSISTANT: Please give me a minute.

USER: Sure, take your own time.

ASSISTANT: I found a flight in Delta airlines with price 200. Shall I book the ticket?

USER: Please reserve my ticket with this airlines.

ASSISTANT: Your ticket is confirmed and the flight number is 1008.

USER: Thank you for booking my ticket.

ASSISTANT: Thank you for choosing us.