You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Thomas Nelson here. I want to book a flight ticket from BOS to DCA. Can you help me in that?

ASSISTANT: Sure, may I know your travelling dates?

USER: My travel dates are Oct 21 to Oct 23.

ASSISTANT: Kindly provide your price limit.

USER: I can afford up to 200.

ASSISTANT: Please wait for  aminute.

USER: Sure.

ASSISTANT: There is no flight available with mentioned dates.

USER: Ok, not an issue. Thank you for your help.

ASSISTANT: Thanks for reaching us.