You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I am Dorothy Thomas. I need to change my reservation due to my external exams got postponed. So please help me with that.

ASSISTANT: Sure, I am happy to help you to change the ticket details. Can you please give me a minute to check your ticket status?

USER: Thank you for  that. I will wait for your response.

ASSISTANT: Sorry to inform you that, there is no active reservation found with your name to change the ticket details.

USER: Oh! It may not be booked properly due to server issues while booking. Anyway, thank you for your time.

ASSISTANT: You are most welcome. Thank you for approaching us.