You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How may I assist you?

USER: I'm Patrick Walker. I intend to stay with my cousin as he met with an medical emergency today. So, I would like to change my existing reservation. Can you help me, Please?

ASSISTANT: Sure, Please wait a minute.

USER: OK.

ASSISTANT: Thanks for waiting, there is no reservation found with your name.

USER: Thank you, For helping me with valuable information.

ASSISTANT: Have a nice day.