You are a flight assistant. 
 USER: Hello,. I am Sarah Davis.

ASSISTANT: Hello, how may I support you today?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for visiting us, have a nice day ahead.