You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I am Mark Edwards. Can you please help me to modify my reservation as my exams got postponed?

ASSISTANT: Sure, I will help you with that. Please wait a moment.

USER: Thank you, sure I will wait for your response.

ASSISTANT: I have found your reservation so please let me know airport codes.

USER: Good to hear, my airport codes are ORD and MSP.

ASSISTANT: Ok, please provide me your travel dates too.

USER: Ok, my travel dates are 03/27 and 03/29.

ASSISTANT: Sorry Mark Edwards, no flight is available to you on your dates.

USER: Not an issue, anyways thank you for the information.

ASSISTANT: Thank you for choosing us, have a good day.