You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure, may I know your name?

USER: Angela Mitchell here.

ASSISTANT: Please give me a moment to check your ticket status.

USER: Ok.

ASSISTANT: Sorry Angela Mitchell, no reservation is available by your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for approaching us.