You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you now?

USER: Owing to an emergency, my business conference got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I can help you in changing process also with out any charge. Can I know on whose name the ticket booking is done?

USER: Sure, I have a existing reservation with name Jessica Turner.

ASSISTANT: Wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no previous flight ticket booking found user the user name to change it.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: You are welcome and have a nice day.