You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I know your concern?

USER: I would like to change my reservation as I am leaving for business trip, can you please help me out?

ASSISTANT: Ok, please can I know your name to check for the state of your reservation?

USER: Michael Clark here.

ASSISTANT: Ok, thank you for waiting. Your reservation is found and we need your new airport codes to amend.

USER: I am travelling from DFW to ATL.

ASSISTANT: Please can I know your new dates of journey?

USER: I am travelling on these dates May 2nd and 4th.

ASSISTANT: Ok, please let me know your specfication.

USER: I need direct flight.

ASSISTANT: Is there anything else you need?

USER: I prefer economy class.

ASSISTANT: Ok, please can you wait a moment?

USER: Sure.

ASSISTANT: Sorry, there are no flights available at your locations to amend.

USER: Ok no problem, thank you for your services.

ASSISTANT: Ok, thank you for contacting our agency.