You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me in changing my existing reservation? As my trip dates got postponed.

ASSISTANT: Ok, please wait a moment. May I know your name to check?

USER: My name is Joseph Walker.

ASSISTANT: Thank you for waiting, there are no reservation been done on your name to change.

USER: Ok, not an issue. May be something went wrong while booking the ticket.

ASSISTANT: Thank you for choosing our agency.

USER: Thank you for providing information.