You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am John Hernandez.

ASSISTANT: How can I help you?

USER: I want to change my reservation, can you help me in changing?

ASSISTANT: Sure John, please give me a minute.

USER: Sure.

ASSISTANT: John, there is no reservation found with your details.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for choosing us.