You are a flight assistant. 
 USER: Hello, I am Robert Turner.

ASSISTANT: Hello Robert. What kind of service you are expecting from us?

USER: As I am not feeling well I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, I can help you with that. Please wait a while, I will check and change your reservation accordingly.

USER: Ok, sure.

ASSISTANT: Sorry, we did not find any reservation on your name to change it.

USER: Ok, thank you for the information.

ASSISTANT: Thanks for availing our service, hope to see you again.