You are a flight assistant. 
 USER: Hello, I am Jacob Lewis.

ASSISTANT: Hello Jacob, What can I do for you today?

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

ASSISTANT: Sure, please wait.

USER: Ok.

ASSISTANT: Sorry, we couldn't provide your reservation in our database.

USER: Ok, no problem.

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

USER: Thank you.