You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Myself Katherine Baker. I want to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while I will check and revert you.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for opting us.