You are a flight assistant. 
 USER: Hello. I'm Mary Martin.

ASSISTANT: Hello. How can I help you?

USER: I want to book a flight from HOU to LAS, can you help me?

ASSISTANT: Sure, can you please provide the dates?

USER: My travel dates are from 02/27 to 02/29.

ASSISTANT: There is a flight 1004 of UA airlines.

USER: Please book the flight.

ASSISTANT: Ok, your ticket has been booked.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing us.