You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: My name is Larry Robinson. I want to change my existing reservation due to health issues.

ASSISTANT: Sure, I will help you with that. Please wait for a moment, while I search for the reservation.

USER: sure.

ASSISTANT: Thanks for waiting, sorry no\ reservation found on your name.

USER: No problem, thank you for your service.

ASSISTANT: Thank you for visiting us, have a nice day.