You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Due to some health issues, I want to change my existing reservation. Will you help me in that?

ASSISTANT: Sure, we are here to help you.

USER: Thanks.

ASSISTANT: May I know your name?

USER: Helen Roberts here.

ASSISTANT: Ok, wait for a while I will check the reservations on your name and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting there is no reservation found on your name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thanks for approaching us.