You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Ryan Lee.

ASSISTANT: How may I help you?

USER: Due to sudden meeting, I would like change my existing reservation. Can you help me?

ASSISTANT: Sure, please wait a moment.

USER: Ok, take your time.

ASSISTANT: Ryan, no reservation has been found on your name.

USER: Oh! its ok, no issues. Thank you for the information.

ASSISTANT: Thank you for approaching us.