You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Pamela Garcia here, can you please change my existing reservation?

ASSISTANT: Sure, I am here to help you. Please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found on your name. Thank you for choosing us, have a nice.

USER: It's ok, not an issue for me. Thanks for checking.

ASSISTANT: Welcome.