You are a flight assistant. 
 USER: Hello. Is this flight ticket booking agency?

ASSISTANT: Hello. Yes, you are at right place. What can I do for you?

USER: I want to do some changes in the existing reservation because my friends are not able to come on the those dates. Can you please help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Could you please provide your name to check your previous reservation status.

USER: Sure, my name is Kathleen Roberts.

ASSISTANT: Ok Kathleen, wait a minute. Sorry Kathleen, there is no reservation found under your name in our records.

USER: It's ok, no problem. Thank you for your information.

ASSISTANT: Ok, thank you for reaching our service, have a nice day.