You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I am Samuel Martin, my planned visit to my parents got postponed, so I want to change my existing reservation. Could you please help me in changing my existing reservation.

ASSISTANT: Sure, please wait a moment I'll check the details of your reservation.

USER: Ok.

ASSISTANT: Sorry to say, no details found in my database regarding your reservation.

USER: Ok, not an Issue.

ASSISTANT: Thanks for availing us, have a nice day.

USER: Thanks for your information.