You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Due to health Issue, I want to change my existing reservation. Can you help me out?

ASSISTANT: Yes, I can help you with that. May I know on which name the ticket was ticket?

USER: Sure, the ticket has been booked on the name of Rebecca Phillips.

ASSISTANT: Ok, please hold on for a moment.

USER: Ok.

ASSISTANT: Sorry, I could not find any ticket booked on your name.

USER: That's fine, thank you.

ASSISTANT: Thank you for reaching us.