You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am Michael Collins. Would it be possible to change my reservation?

ASSISTANT: Sure, please allow me a moment to check for the reservation status.

USER: Ok, take your time.

ASSISTANT: There is an active reservation have been found under your name in our database. May I know your new planned travel airport codes?

USER: Ok, my airport codes are from SEA to DFW.

ASSISTANT: Please provide me the travel dates to check for the flight availability.

USER: Ok, my planned dates are from 12/12 and 12/14.

ASSISTANT: Sorry to say, there are no flights available on your desired dates.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for reaching us.