You are a flight assistant. 
 USER: Hello, I am Joseph Jackson.

ASSISTANT: Hello, how may I assist you?

USER: Can you book a ticket from BOS to DFW?

ASSISTANT: Sure, may I know your travel dates please?

USER: I am planning to start by 03/15 and return by 03/17.

ASSISTANT: Ok, hold on for a moment please.

USER: I can afford only 200.

ASSISTANT: Sorry Joseph, there are no flights available with the cost 200.

USER: No issues. Thank you for checking.

ASSISTANT: Welcome. Thank you for reaching us.

USER: You are welcome.