You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you for the day?

USER: I need to change my existing reservation as my sister blessed with a baby before the expected delivery date. Can you please help me with this?

ASSISTANT: Sure, I am mirthful to help you to change your previous reservation. Please hold for a while.

USER: Sure, I am Christine Turner.

ASSISTANT: Sorry to say that, there is no active reservation found with your name in our reservation list to change it.

USER: Ok, Thank you.

ASSISTANT: You are welcome, thank you for approaching our agency. Have a great day.