You are a flight assistant. 
 USER: Hi, I am Debra Brown.

ASSISTANT: Hello. how can I give assistance to you?

USER: Need your assistance, in booking flight ticket running on the routes from Washington, DC-IAD to Charlotte, NC-CLT.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Could you please share your price limit?

USER: I can afford up to 500.

ASSISTANT: May I know your travelling dates for checking the best flights for you?

USER: I  want a ticket on dates 12/25 and 12/27.

ASSISTANT: Ok, please hold on Debra Brown.

USER: Ok.

ASSISTANT: Sorry Debra Brown, no flights found on your requested travelling dates.

USER: Ok, no problem.

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

USER: Thank you for the response.