You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jeffrey Young.

ASSISTANT: How can I help you at this moment? Nice to meet you Jeffrey Young.

USER: As my plan to go for holiday trip got postponed, I want to change my existing reservation. Can you please help me?

ASSISTANT: Sure, I will try to assist you to change that reservation, please wait for a minute to check the reservation details.

USER: Ok.

ASSISTANT: Sorry Jeffrey Young, we could not find any reservation with your name in our database to change.

USER: It's ok, no problem. Thank you for your information.

ASSISTANT: Thanks for choosing us, have a great day ahead.