You are a flight assistant. 
 USER: Hello. I am Deborah Perez.

ASSISTANT: Hello, how may I assist you?

USER: Will you please help me in changing my existing reservation as my plan to attend a seminar got postponed?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your given name.

USER: It's ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for choosing us.