You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Michelle Clark here. Due to dense fog in Boston, I will not be able to travel from Detroit. Could you amend my reservation?

ASSISTANT: Sure, I am here to help you. Please wait while I check for your reservation in our portal.

USER: Sure.

ASSISTANT: Reservation found on your name, can I know your new airport codes?

USER: My genesis and terminus airport codes are DTW and BOS.

ASSISTANT: Ok, when are you willing to travel?

USER: My itinerary dates are Mar 19 and Mar 21.

ASSISTANT: Do you need any impasse in your journey?

USER: I prefer direct flight.

ASSISTANT: Ok, would you like to travel in any specific airline?

USER: I have no other specifications.

ASSISTANT: Ok, please stand by.

USER: Sure.

ASSISTANT: Sorry, no flights found as per your request.

USER: No problem, I will find an alternative mode of transport.

ASSISTANT: Thank you for contacting us.

USER: Thank you for assisting me.