You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I have to change my recent ticket because my health is not good. So, I am unable to travel in this dates. Can you help me?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your name please for checking your reservation?

USER: My name is George Scott.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry George Scott, no reservation has found under your name to change.

USER: It's ok, not an issue. Thank you for searching.

ASSISTANT: Thank you for choosing us, have a great day.