You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I would like to change my existing reservation, due to postpone of my seminar. Will you please avail me in changing?

ASSISTANT: Sure, let me know your name to check your reservation details.

USER: Susan Wright is here.

ASSISTANT: Thank you, please wait for a moment.

USER: Ok.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.