You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I have planned a trip last week and I had booked a ticket but suddenly my manager called me and told that there is an important meeting. Can you please help me in flight ticket changing?

ASSISTANT: Sure, I am here to help you.

USER: Thank you for considering my request.

ASSISTANT: May I know your good name.

USER: My name is Helen Wilson.

ASSISTANT: Please wait for a moment.

USER: Ok, I will wait for your reply. Take your time.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: It's ok, not a problem with that one. Thank you for your information.

ASSISTANT: Thank you for reaching us.

USER: You are most welcome.