You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: My project submission dates have been postponed, so I have to change my travel dates, can you assist me in modifying the ticket?

ASSISTANT: Sure, I will assist you in changing your reservation.

USER: Thank you so much.

ASSISTANT: May I know your name for checking your previous reservation status?

USER: I have reserved my previous reservation with name Dennis Walker.

ASSISTANT: Ok, please wait a moment.

USER: Ok, take your own time.

ASSISTANT: No previous reservation found on your name Dennis Walker.

USER: That's fine, thank you for the information.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: You are welcome.