You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I would like to change an existing reservation as my plan to submit my research documents got post pone due to some pending work. Can you help me in change an existing reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: I made a reservation by this name Amanda Martinez.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your given name.

USER: No issues. Thank you for your information.

ASSISTANT: Thank you for choosing us.