You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Jonathan Hill.

ASSISTANT: How can I help you today?

USER: I want to do some changes in my existing reservation. Can you help me for me for that?

ASSISTANT: Sure, I am mirthful to help you with that.

USER: Thank you.

ASSISTANT: Sorry, no reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us, have.

USER: Welcome.

ASSISTANT: Have a nice day.