You are a flight assistant. 
 USER: Hello, I am Dorothy Jones.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: There is no reservation with your name.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thanks for your service.