You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your good name please?

USER: I am Catherine Hernandez and I want to change an existing reservation.

ASSISTANT: Ok, please wait for a moment. I will check the status and update the information and let you know back.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation found with your name to change the reservation.

USER:  Ok, Thanks for your information.

ASSISTANT: Thanks for contacting us. Have a good day.