You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I intend to travel from Charlotte to meet my manager at Dallas & Fort Worth. Can you help me book a flight ticket within the price of 200?

ASSISTANT: Sure, I would be happy to help you. Can you please help me with your travelling dates?

USER: I would like to travel on 05/28 and 05/30.

ASSISTANT: May I know your takeoff and landing airport codes please?

USER: My trip is from CLT to DFW.

ASSISTANT: May I know your good name please?

USER: My name is Sarah Johnson.

ASSISTANT: OK, please a wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no flight with your respective dates of travel.

USER: It's ok, thank you for the response.

ASSISTANT: Thank you for choosing us.