You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I want to change my existing reservation due to postpone of my exams, can you help me with that?

ASSISTANT: Sure, I am perky to help you. Please provide your good name to proceed further.

USER: I am Linda Thompson.

ASSISTANT: Sorry, there is no active reservation on your name in our records.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for contacting us.