You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Melissa Moore here.

ASSISTANT: How may I guide you?

USER: Can you book me a flight ticket from HOU to DEN?

ASSISTANT: Sure, please provide your travel dates.

USER: I am planning to travel from 07/25 to 07/27.

ASSISTANT: There is a flight for you in UA airline with flight number 1027.

USER: Ok, please proceed.

ASSISTANT: Your ticket has been confirmed.

USER: Thank you.

ASSISTANT: Thank you for choosing us.