You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Nancy Parker here. I would like to change my existing reservation, could you help me that please.

ASSISTANT: Sure, I will help you with that. Please wait for a while.

USER: sure.

ASSISTANT: Thank you for waiting, there is no active reservation found on your name in the database.

USER: No issue, Thank you for the information provided by you.

ASSISTANT: Thank you for availing us.