You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation as my friends Comic con is rescheduled.

ASSISTANT: Ok, I will help you for that. Please provide your name.

USER: I am Jerry Phillips.

ASSISTANT: Sorry, no reservation found on your name. Thanks for opting us.

USER: Ok, not a problem. Thank you.