You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this moment?

USER: Myself Helen Miller. I would like to change my recent reservation due to some personal issues, will you help me with that?

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

USER: Thank you for accepting my request.

ASSISTANT: Please wait for a minute.

USER: Ok, I will wait for you response.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: Ok, not a issue,. Thank you for your information.

ASSISTANT: Thank you for approaching us.