You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Is there immediate assistance that you are seeking from our agency?

USER: I got an important work, so I am unable to travel now. Can you please help me in changing the details of my previous ticket?

ASSISTANT: Sure, I can help you in that one.

USER: Thank you for accepting my request.

ASSISTANT: May I know your name for checking your previous ticket reservation in our data base?

USER: My name is Emma Wright.

ASSISTANT: I am happy to say that I have found your reservation and may I know your dates please?

USER: That's great, my changed travel dates of my trip are 11/16 and 11/18.

ASSISTANT: May I know your preferable airport codes?

USER: The airport codes that I prefer to travel are MCO and OAK.

ASSISTANT: Please allow me a moment.

USER: Sure, take your time.

ASSISTANT: I would like to say that there is no flight for you to book a ticket to reach your destination.

USER: It's ok, not a problem with that. Thank you for helping me in searching the flight.

ASSISTANT: It's my pleasure and have a nice day.