You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: As I am planning to attend a seminar at Houston, TX - HOU. Can you help me book a flight ticket from Dallas & Fort Worth, TX - DFW?

ASSISTANT: Sure. Kindly assign your preferred dates of travelling?

USER: My travel dates are 10/18 and 10/20.

ASSISTANT: May I know your name?

USER: Ryan Campbell is my name.

ASSISTANT: Do you need any connecting flight?

USER: I need a direct flight.

ASSISTANT: Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: Ok, thank you for the response.

ASSISTANT: Thank you.