You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Alexander Nelson.

ASSISTANT: How can I assist you today?

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

ASSISTANT: Sure, I will assist you Alexander.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name in our data list.

USER: Ok, no issues.

ASSISTANT: Thank you for choosing us.

USER: Thank you.