You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Myself Katherine Clark. Can you please help me to change my existing reservation?

ASSISTANT: Sure, I can help you with that.

USER: Ok.

ASSISTANT: Please allow me moment to check the details.

USER: Ok.

ASSISTANT: Katherine, I have checked and see that there is no reservation found under your name.

USER: Ok, that's fine. Thank you for your help.

ASSISTANT: You are welcome. Thank you for contacting us.