You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, can I help you?

USER: I am Jonathan Green. Owing an emergency want to change my reservation, can you help me with it please?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Sorry, we could not a find any reservation in our database on your name.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for availing us.