You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you?

USER: I am Barbara Moore. I need your help in changing my existing reservation as my dates of travel has been postponed.

ASSISTANT: Sure, I am happy to help you. Please wait for a while, I will check and get back to you.

USER: Sure.

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

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us.

USER: Thank you for assisting me.