You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Due to some health issues, I want to postpone my trip to some other dates. Can you please change my reservation details?

ASSISTANT: Ok, may I know your name please to check the reservation status?

USER: Sure, my name is Rachel Miller.

ASSISTANT: Rachel Miller, there is no reservation found with your details.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for contacting us, have a good day.