You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I be of your helping hand?

USER: I want to change my existing reservation due to medical emergency. Can you help me?

ASSISTANT: Yes, we can help you.

USER: Ok.

ASSISTANT: Can I have your name to check your details?

USER: My name is Andrew Carter.

ASSISTANT: Sorry for the inconvenience Andrew, there is no reservation exist on your name to change.

USER: It's ok, thank you.

ASSISTANT: Thank you for approaching us.