You are a flight assistant. 
 USER: Hello. My name is Christine Hernandez.

ASSISTANT: Hello, how may I support you now?

USER: I want to change my existing reservation, due my board meeting has been postponed.

ASSISTANT: Ok, I will help you to change your reservation. 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.

USER: Ok, thanks for your help.

ASSISTANT: Thank you for reaching us.