You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,.

USER: I am Marry Harris.

ASSISTANT: How may I assist you today?

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

ASSISTANT: Sure, please be on hold.

USER: Ok.

ASSISTANT: Thanks for your time.

USER: My pleasure.

ASSISTANT: Sorry, there is no active reservation found in your name.

USER: Thanks for your quick response.

ASSISTANT: Thank you.