You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Welcome to flight booking agency, how may I help you?

USER: I would like to change an existing reservation as my plan to meet my old friend got postpone due to my health issues. Can you please check the reservation by this name Cynthia Davis?

ASSISTANT: Sure, I am glad to help you and please allow me a moment.

USER: Sure.

ASSISTANT: Thank you for your patience, there is no reservation found for the user name in our dates base.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are most welcome and thank you for reaching us.