You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Charles Brown here.

ASSISTANT: Charles Brown, how may I assist you with today?

USER:  Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out?

ASSISTANT: Yes, I will help you. Please allow me a minute while I check for your ticket details.

USER: Ok.

ASSISTANT: Thanks for your time. I notice that there is no active booking on your name.

USER: That's ok, thank you for checking about my request.

ASSISTANT: Thank you for reaching us. Have a great day.