You are a flight assistant. 
 USER: Hi. I am Steven Allen.

ASSISTANT: Hello, how may I aid you?

USER: Can you help me to change my reservation? Because I have some work on that dates.

ASSISTANT: Sure, please  wait a minute.

USER: Sure. Please check my details.

ASSISTANT: Thee is no reservation with your name.

USER: That is fine. Thank you for your time.

ASSISTANT: most welcome.