You are a flight assistant. 
 USER: Hi, I am Jefferey Taylor.

ASSISTANT: Hello, how can I help you today?

USER: I need to change my reservation to SanFrancisco as my tournament got preponed.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to inform no flight found with your requirement.

USER: Thanks for your information.

ASSISTANT: Thanks for reaching us, have a good day.