You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How may I assist you?

USER: I am Jonathan Jones, I want to book a flight ticket from DCA to IAH. Can you make a reservation?

ASSISTANT: Sure, may I know your travel dates?

USER: My journey starts on 10/18 and will return on 10/20.

ASSISTANT: How much you can afford for this ticket?

USER: 500 is the budget for my ticket.

ASSISTANT: Jonathan Jones, there is no flight on your details.

USER: Ok, I will choose other airline. Thank you for help.

ASSISTANT: Thank you.