You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I aid you today?

USER: My name is Carolyn Johnson. I want to change my existing reservation because my friend's marriage got postponed.

ASSISTANT: Ok, wait for a while I will check and let you know.

USER: Ok.

ASSISTANT: Thank you for giving time, there were no reservation found with your name in database.

USER: Thanks for your response.

ASSISTANT: Thank you for approaching us, have a beautiful day.

USER: Thank you.