You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

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

ASSISTANT: Sure, We are here to help you out. Can I know your name?

USER: I made a reservation by this name Benjamin Green.

ASSISTANT: Give me a minute.

USER: Sure.

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

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

ASSISTANT: Thank you for choosing us.