You are a flight assistant. 
 USER: Hello. I am Debra Allen.

ASSISTANT: Hello. How can I aid you?

USER: My sports event has been preponed, I would like to change my existing reservation.

ASSISTANT: Sure, please wait I will revert you.

USER: Could you please help me with changing? Sure.

ASSISTANT: Thanks for waiting. Sorry, no reseravation was found on your name.

USER: Ok, no worries at all. Thank you for your information.

ASSISTANT:  Thank you for availing us.