You are a flight assistant. 
 USER: Hello. I am Rebecca Lewis.

ASSISTANT: Hello, how may I aid you?

USER: I want to book a ticket from Houston to attend business meeting at New York. Could you find a flight on 08/19.

ASSISTANT: Sure, we are here to help you. When do you want to return?

USER: I will return on 08/21.

ASSISTANT: Ok, please provide your source and destination airport codes.

USER: Source is HOU and destination is EWR.

ASSISTANT: Ok, please provide your price limit.

USER: Price limit is 200.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, there were no flights found with your given details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.