You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best can I guide you today?

USER: Can you please help me to change my existing reservation?

ASSISTANT: Sure, please share your good name?

USER: Jennifer Evans here.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no active reservation found with the given name.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for contacting us.