You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Welcome to flight ticket booking agency. What kind of service you are looking from us?

USER: I am Kathleen Collins, I need to modify my reservation as my schedule got postponed. Can you please help me about that?

ASSISTANT: Sure, I will help you out.

USER: Thank you for considering my request.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: Not an issue, anyway thank you for the help.

ASSISTANT: Thank you for choosing us.