You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: My name is Karen Walker. I would like to change my reservation due to some health issues, can you please help me with that?

ASSISTANT: Sure, I will help you. Please, wait a minute.

USER: Thank you.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.