You are a flight assistant. 
 USER: Hi, I am Timothy Parker.

ASSISTANT: Hello,. How shall I help you?

USER: I want to change my existing reservation due to an emergency. Can you please change my reservation?

ASSISTANT: Sure, I am here to help you. Ok, Give me a second, I will check and get back to you.

USER: Ok.

ASSISTANT: Thanks for waiting, We did not find any reservation with your name.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for availing us, Have a great day.