You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you now?

USER: Gregory Rodriguez here, due to sudden changes I want to alter my reservation. can you please help me with it?

ASSISTANT: Sure, I can help you. Please wait, I will check the status and revert to you.

USER: Ok.

ASSISTANT: Sorry, we did not find any reservation has been registered with us on your name.

USER: Not an issue, thank you.

ASSISTANT: Thanks for consulting us, have a nice day.