You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Will you please assist me to change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Sure, please may I know your name?

USER: I made a reservation by this name Sharon Young.

ASSISTANT: Sorry, there is no active reservation found under your name in our database.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Most welcome.