You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: My name is Virginia Anderson, I want to change my existing reservation due to postpone of my friend engagement.

ASSISTANT: Ok. Please wait a moment.

USER: Sure.

ASSISTANT: We found a reservation on your name. Can you please share your travelling details?

USER: My source and destination airport codes are CA - SFO, CO - DEN. My departure day is 11/07, return day is 11/09.

ASSISTANT: Sorry, there were no flights found on your route.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.