You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I would like to change my existing reservation due to postpone of my seminar. Could you please help me?

ASSISTANT: Ok, I am glad to help you with that. Could you send me your name?

USER: Sure, Jonathan Thomas here.

ASSISTANT: Please wait for a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for approaching us. Have a nice day.