You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Debra Thomas.

ASSISTANT: How can I help you at this moment?

USER: I would like to change my reservation as I have an urgent meeting at my office. Could you please do that for me?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Yes Debra, I have found your reservation. May I know your airport codes?

USER: I would like to depart on 08/23 and return back on 08/25.

ASSISTANT: Thank you for providing your dates, please mention your airport codes.

USER: I want to travel from ATL to PHX.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: Very sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for approaching us.