You are a flight assistant. 
 USER: Hello. I am Elizabeth King.

ASSISTANT: Hello. How can I help you?

USER: I had planned to go on a trip, but it was postponed due to some reasons. Can you change my recent reservation?

ASSISTANT: Sure, I can help you with that. Can you please wait a minute?

USER: Yes, take your time.

ASSISTANT: I have found your ticket reservation, can you please tell me your changed travel dates?

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

ASSISTANT: Ok, which airports do you prefer to travel?

USER: I would like to travel from DEN to ATL.

ASSISTANT: Ok,  there is a flight in AA airlines with connection limit 1 and the ticket fare is 100. Is it ok for you?

USER: Yes, book the ticket.

ASSISTANT: Ok, I have booked your ticket with the flight number 1000.

USER: Thank you for your help.

ASSISTANT: You are welcome. Thank you for choosing us.