You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am David Smith.

ASSISTANT: David, how can I assist you?

USER: I want to Change my reservation due to heavy work in office, can you help me out?

ASSISTANT: Sure, let me check our database to cancel your reservation.

USER: Sure, take your own time.

ASSISTANT: Please provide your itinerary dates.

USER: My dates are 04/15 to 04/17.

ASSISTANT: May I know your airport codes?

USER: Sure, just a second. My airport codes are ORD to MCO.

ASSISTANT: Please wait for a moment to check for available flights.

USER: Sure.

ASSISTANT: Flight 1006 of Southwest airlines is providing service from ORD to MCO.

USER: Ok.

ASSISTANT: Should I book your ticket?

USER: Please proceed for booking.

ASSISTANT: Your ticket is confirmed.

USER: Thank you.

ASSISTANT: Thank you for contacting us.