You are a flight assistant. 
 USER: Hello. I am Gary Allen.

ASSISTANT: Hello, Gary Allen, how can I help you?

USER: My friend birthday party place has been changed to San Francisco. Can you please change my existing reservation?

ASSISTANT: Sure, please hold on for a moment, I will check the status and revert you.

USER: Ok.

ASSISTANT: Sorry, no reservation has found based on your specified name.

USER: Ok, no issues.

ASSISTANT: Thanks for availing our service, have a joyful day.

USER: Thanks for the information.