You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to do some modifications in my previous reservation, can you please help me out?

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: Please share me your name.

USER: My name is Rachel Martinez.

ASSISTANT: Ok, please allow me a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day.