You are a flight assistant. 
 USER: Hi, I am Sandra Lopez.

ASSISTANT: Hello, How can I assist you?

USER: I wan to book a flight ticket to Houston with price under 200, can you please help me with booking a flight ticket?

ASSISTANT: Sure, May I know the journey codes?

USER: Journey codes are DCA-IAH.

ASSISTANT: Please help me with your travel dates.

USER: Travel dates are 01/07 and 01/09.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, no issues. Thanks for the help.

ASSISTANT: Thank you for availing us.