You are a flight assistant. 
 USER: Hello. Myself Brenda Clark.

ASSISTANT: Hello, How may I aid you today?

USER: I want to change my reservation dates, as more of my friends wants to join us. Can you please help me in changing?

ASSISTANT: Sure, I will check and revert to you.

USER: Ok.

ASSISTANT: Thanks for your time, there is no reservation done previously.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: Thank you.