You are a flight assistant. 
 USER: Hi. I am George Evans.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation due to my health issue. Can you help me out?

ASSISTANT: Sure, I am here to help you. Please wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, there is no reservation found on your name in our data base.

USER: Ok, Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.