You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Stephanie Robinson. I want to change my existing reservation due to the change in my holiday trip. Can you help me?

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Ok, take your own time.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: That's ok, no issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.