You are a flight assistant. 
 USER: Hi. My name is Barbara Lopez.

ASSISTANT: Hello, how may I assist you?

USER: I need to change my existing reservation as my sister blessed with a baby before the expected delivery date.

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation found.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.