You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, may I know your name?

USER: Myself, Melissa Edwards.

ASSISTANT: Please give me a moment to check your ticket status.

USER: Ok.

ASSISTANT: Sorry Melissa Edwards, no reservation is available by your name.

USER: Ok, no issues. Thank you for checking.