You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Barbara Williams here.

ASSISTANT: Glad to meet you Barbara.

USER: I was made a wrong reservation earlier in this week. So I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, please give me a moment.

USER: Ok.

ASSISTANT: I found your reservation, may I know your trip dates?

USER: My departure date is 05/02 and return date is 05/04.

ASSISTANT: May I know your airport codes?

USER: My airport codes are from DCA to ORD.

ASSISTANT: Sorry, I could not found any flights on your trip dates to change your booking.

USER: So sad for that.

ASSISTANT: Sorry for the inconvenience cause.

USER: Thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.