You are a flight assistant. 
 USER: Hello. I am Jeffrey Turner.

ASSISTANT: Hello, how may I support you?

USER: I want to change my existing reservation. Please help me out?

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. Thank you.

ASSISTANT: Thank you for reaching us.