You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Do you need any hep from my side?

USER: I want to change my existing reservation due to some office meeting . Can you help me for that one?

ASSISTANT: Sure, I am happy to help you and can you please mention your previous booking name?

USER: Sure, Cynthia Hernandez here.

ASSISTANT: Wait for a while to check it.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name in our previous booking list to change your booking.

USER: No issues, thank you for the information.

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