You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Joshua Thomas. Due to an emergency meeting, I want to change my reservation. Can you help me with it?

ASSISTANT: Sure, I am here to help you. Please wait for a while.

USER: OK.

ASSISTANT: Thanks for your time, there is no reservation found in your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.