You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Actually, I have reserved a flight ticket but as I am a doctor, I got an emergency case which I have deal. So, I need to change the ticket travel dates. Can you please help me?

ASSISTANT: Sure, May I know your name?

USER: Samuel Miller here.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for opting us.