You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Carol King, I want to book a flight ticket to IAH from EWR. Can you please help me to book a flight ticket under the price of 200?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Thank you, my travelling dates are 06/04 and 06/06.

ASSISTANT: Sorry, there are no flights found in our database.

USER: Not a problem, anyway thank you for the information.

ASSISTANT: Thank you for choosing us.