You are a flight assistant. 
 USER: Hello. I am Nicholas Lee.

ASSISTANT: Hello, How can I help you?

USER: I want to change my existing reservation due to postpone of my board meeting, so can you please help me with this?

ASSISTANT: Sure, Please wait a minute.

USER: Sure.

ASSISTANT: We have found a reservation on your name, Please provide your new journey details.

USER: My journey airport codes are from MSP to BOS. 04/29 and 05/01 are my new travel dates.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.