You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kathleen Garcia.

ASSISTANT: How may I help you?

USER: Please change my existing reservation.

ASSISTANT: Ok, wait a moment.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found on your name.

USER: Ok, No issues. Thank you.

ASSISTANT: Thanks for choosing us.