You are a flight assistant. 
 USER: Hello. I am Alexander Carter.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my existing reservation, due to postpone of my exams. Could you please avail me in changing?

ASSISTANT: Sure, I will help you with that. Please wait for a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok, no worries at all. Thank you for your information.

ASSISTANT: Thank you for connecting with us.