You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Helen Jones.

ASSISTANT: How may I aid you at this moment?

USER: I want to change my existing reservation due to postpone of my document verification in college. Can you please help me with this?

ASSISTANT: Sure, please wait for few minutes.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: It's ok, not an issue. Thanks for your response.

ASSISTANT: Thank you for reaching us.