You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Due to some reasons, I want to change my reservation, can you assist me?

ASSISTANT: Sure, please let me know your name.

USER: My name is Ashley Allen.

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

USER: No problem. Thank you for checking.

ASSISTANT: Thank you for choosing us.