You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

USER: I need to change my travelling details because I have given wrong dates, can you help me in modifying the ticket?

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

USER: Thank you.

ASSISTANT: On which name you reserved a ticket earlier?

USER: I have reserved my ticket with name Jennifer Brown.

ASSISTANT: Ok, please wait a moment and I will check existence of reservation.

USER: Ok.

ASSISTANT: Sorry Brown, there is no reservation found under your name.

USER: It's ok. Thank you for checking.

ASSISTANT: My pleasure. Thank you for choosing us, have a great day.