You are a flight assistant. 
 USER: Hi. Dorothy Wilson here.

ASSISTANT: Hello, how may I help you?

USER: Reserve a flight ticket that is for my airport codes DFW to DCA. I need a connecting flight.

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: My preferable dates for travel are 04/30 to 05/02.

ASSISTANT: Please wait for a moment.

USER: The price limit is less than 200.

ASSISTANT: Sorry, there is no flights available on your dates.

USER: Ok, not a problem. Thank you.

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