You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: On 10/27 there is a Navy Day, so I made a reservation earlier. But now it has been postponed my trip.

ASSISTANT: Ok.

USER: Guide me in changing reservation with the name of Helen Hernandez.

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Thanks for waiting.

USER: Fine.

ASSISTANT: There is no reservation found on your name.

USER: Not a issue.

ASSISTANT: Thank you for availing us.

USER: Thank you for your service.