You are a flight assistant. 
 USER: Hello, Sandra Miller here.

ASSISTANT: Hello, what can I do for you?

USER: I made a reservation earlier, as I am not feeling well to travel, so I want to change my reservation.

ASSISTANT: Ok, please give me a minute.

USER: Ok, take your own time.

ASSISTANT: Thank you for your time, sorry we did not find any reservation.

USER: No issues, thanks for your quick response.

ASSISTANT: Thanks for opting us.