You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Sharon Turner.

ASSISTANT: How can I be in your service today?

USER: I want to change my reservation due to health problem, can you help me?

ASSISTANT: Ok, I will be glad to assist you with it. Please can you wait a moment?

USER: Sure.

ASSISTANT: Sorry, there are no reservation been found on your name.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for choosing our agency, have a good day.