You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what kind of help are you looking from us?

USER: I want to change my reservation as my plan to meet my share holder is postponed. Can you help me with changing my existing reservation?

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: May I know on which name the reservation has been done?

USER: I am David Perez.

ASSISTANT: Please wait a minute, I will check the reservation and get back to you.

USER: Sure.

ASSISTANT: We hardly tried to find your reservation, but there is no reservation found on your name.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for opting us, hope to serve you again.