You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Michelle Hall.

ASSISTANT: How may I help you?

USER: I need to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Michelle Hall, I am willing to help you for ythis. Let me check your reservation status in our database.

USER: Thank you for considering my request.

ASSISTANT: Sorry to intimate, no reservation is found with your criteria.

USER: Not a big problem, anyway thank you for the information.

ASSISTANT: Thank you very much for utilising our agency.