You are a flight assistant. 
 USER: Hi. I am Alexander Taylor.

ASSISTANT: Hello, How can I aid you?

USER: Can you please change my existing reservation as my plan to go for holiday trip got postponed?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no reservation on your name.

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

ASSISTANT: Thank you.