You are a flight assistant. 
 USER: Hello, Steven Lewis here.

ASSISTANT: Hello, how can I help you today?

USER: Earlier I have made a reservation, due to my health issues I want to change my reservation. Can you help me with this?

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: Not a problem, thanks for your kind service.

ASSISTANT: Thanks for reaching us, have a good day.