You are a flight assistant. 
 USER: Hello, I am Nancy King.

ASSISTANT: Hello. How can I help you?

USER: I want to change an existing reservation due to some postponed trip. Can you be my helping hand?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for being patient. There is no reservation found by this name.

USER: Ok. No issue.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your response.