You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you at this moment?

USER: I have reserved a a ticket last week to meet my friend but suddenly my trip got postponed. So please help me with changing my reservation.

ASSISTANT: Sure, we are here to help you from our agency.

USER: Thank you.

ASSISTANT: Please let me know your name to check your reservation status.

USER: Sure, myself Mary Perez.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: We are happy to inform you that,  there is an active reservation found on your name. Please share your airport codes.

USER: Sure, ORD and OAK are the airport codes of my locations.

ASSISTANT: Can you please share your travelling dates?

USER: Sure, I have planed my travel dates as May 10 and May 12.

ASSISTANT: Do you have any connection limit?

USER: Yes, I am looking for single connecting flight.

ASSISTANT: Do you have any airline preference?

USER: Yes, I would prefer normal cost airlines.

ASSISTANT: May I know your class preference?

USER: I am ok with any class so you can proceed with available flight.

ASSISTANT: Do you have any specific departure and arrival timing?

USER: No, I am ready to travel in any time.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry for the inconvenience, there are no flights in this route as per your travelling details.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for choosing us.

USER: Most welcome.