You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, welcome to Google booking agency.

USER: My name is Justin Young.

ASSISTANT: What can I do for you Justin?

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, please give me a minute so that I can check the status of your existing reservation,. Sorry to say you that there is no reservation found under your name.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you for reaching our agency.