You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: Gary Young here. I would like to change my recent reservation. Can you help me?

ASSISTANT: Sure, I'll help you in changing an existing reservation. Please wait a moment I'll check the reservation list.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: No issue, thank you for your precious time.

ASSISTANT: Thank you for approaching us.