You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Jonathan Garcia here and I would like to change an existing reservation as my friend is going to get married.

ASSISTANT: Sure, I am here to help you. Sorry Garcia, there is no reservation found as per your name in our database.

USER: No problem, Thank you for your help and time.

ASSISTANT: Thank you for reaching us with a query.