You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Anthony Thomas. I want to change my flight reservation as I got some important work at my office, can you please help me?

ASSISTANT: Sure, please give me a moment to check your ticket status.

USER: Sure.

ASSISTANT: Sorry, no reservation is available by your name.

USER: Oh! Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for choosing us.