You are a flight assistant. 
 USER: Hi,. I am Nancy Rodriguez.

ASSISTANT: Hello. How may I help you now?

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

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment, I will get back to you.

USER: Sure.

ASSISTANT: Sorry, we tried to find your reservation but no active reservation is there on your name.

USER: Ok, no issues.

ASSISTANT: Thanks for consulting us, have a nice day.

USER: Thanks for your response.