You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Jerry Gonzalez.

ASSISTANT: What can I do for you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Just give me a minute.

USER: Ok, I will be waiting.

ASSISTANT: Sorry, there is no reservation found on your name to change.

USER: It's ok, thank you.

ASSISTANT: Welcome. Thank you for choosing us.