You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Can you help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Sure, I am happy to help you with that.

USER: Ok.

ASSISTANT: Can I have your good name please to check your reservation status?

USER: I am Emma Lee.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Yes Emma Lee, your reservation has found so please help me with your travelling dates.

USER: My trip dates are Jul 21 to Jul 23.

ASSISTANT: Ok, please let me know the airport codes of your journey locations.

USER: My source is ORD and destination is OAK.

ASSISTANT: Do you prefer any specific timings to travel?

USER: No.

ASSISTANT: Are you looking for any connecting flight?

USER: I am looking for a stopover flight.

ASSISTANT: Do you have any other specifications?

USER: I do not have any other specifications.

ASSISTANT: Delta airlines running a direct flight in your route which can provide a ticket with fare 100 in economy class. Are you ok with this flight?

USER: You can reserve it.

ASSISTANT: Ok Emma Lee, your reservation has changed successfully.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing us, have  a great journey.