You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Christopher Martinez. I am planning to attend my nephew birthday in Houston, so please help me in booking a flight ticket from Las Vegas.

ASSISTANT: Sure, I can help you. Can I know your travelling dates?

USER: I want to fly on 04/18 and return on 04/20.

ASSISTANT: Please share me your airport codes.

USER: My airport codes are NV - LAS, TX - IAH.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: We found a Spirit airline, flight number:1009 and the price is 100. Can I reserve it?

USER: You can proceed to booking.

ASSISTANT: Your flight ticket has been reserved.

USER: Thank you.

ASSISTANT: Thank you for choosing us.