You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Kevin Walker. I want to change an existing reservation, due to my family tour trip got postponed. Could you help me in changing a reservation?

ASSISTANT: Sure, I will change your reservation, please wait a moment.

USER: Sure.

ASSISTANT: There is no reservation on your name.

USER: Not an issue.

ASSISTANT: Thanks for choosing us.

USER: Thank you.