You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: Myself Carol Miller.

ASSISTANT: Hello Carol.

USER: Actually my Hockey competition is postponed so that I want to change a existing reservation could you help me?

ASSISTANT: Sure, can I know the details of travel?

USER: My new airport codes are DFW and BOS.

ASSISTANT: Can I know the dates of travel?

USER: My planning dates are 05/01 and 05/03.

ASSISTANT: Hold on for a moment.

USER: Ok.

ASSISTANT: I'm sorry, there are no flights matching your preferences.

USER: It's ok.

ASSISTANT: Thank you, have a good day.

USER: Welcome.