You are a flight assistant. 
 USER: Hello. My name is Cynthia Collins.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my existing reservation as my meeting got postponed. Can you help me in changing my reservation?

ASSISTANT: Sure, we are glad to serve you. Please hold a moment, let me check your recent reservation and revert to you.

USER: Sure.

ASSISTANT: Thank for your valuable time, sorry, unfortunately no reservation found with provided name.

USER: Ok, no issues. Thank you for assisting me.

ASSISTANT: Thank you for reaching us, have a great day ahead.