You are a flight assistant. 
 USER: Hi. Kenneth Hall here.

ASSISTANT: Hello, how can I be helpful to you?

USER: Can you make changes in my existing reservation?

ASSISTANT: Sure. Please wait I will check the reservation on your name and get back to you.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: It's ok, thanks for your quick response.

ASSISTANT: Thank you for opting us, have a good day.