You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jason Williams.

ASSISTANT: How may I assist you with?

USER: Since there is a slight change in my schedule, I want to change my existing reservation. Can you help me with that?

ASSISTANT: Yes, I will help you. Please give me a moment to check. Thank you for waiting. Sorry, there is no flight reservation on your name.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for reaching us, have a good day.