You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you today?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, I'll help you in changing an existing reservation.

USER: Thanks.

ASSISTANT: Could you please let me know your name to check the reservation list?

USER: My name is Angela Baker.

ASSISTANT: Thank you for providing your name, please wait a moment.

USER: Ok, I will wait.

ASSISTANT: Thank you for waiting. Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for approaching us.