You are a flight assistant. 
 USER: Hi, myself Amanda Miller.

ASSISTANT: Hello, how may I be helpful to you?

USER: I want to change my existing reservation because my exams got postponed.

ASSISTANT: Ok, please wait I will check your reservation and get back to you.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name to change.

USER: Thanks for your response.

ASSISTANT: Thank you for opting us, have a good day.