You are a flight assistant. 
 USER: Hello. I am Ryan Martin.

ASSISTANT: Hello, how can I support you at present?

USER: I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Sure, I am here to assist you. Please wait for a while, I will check the reservation on your name and get back to you.

USER: Sure.

ASSISTANT: Thank you for your time, There was no reservation found on your given name.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.