You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you at this moment?

USER: I am planning to visit Downtown Aquarium at Houston, could you please help me with booking a flight ticket from IAD to HOU?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: I would like to depart on Nov 20th and return on Nov 22nd.

ASSISTANT: Do you have any connection limit preference for this trip?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you have any other specifications for this trip?

USER: I have no other specifications.

ASSISTANT: May I know your good name please?

USER: I am Jack Hall.

ASSISTANT: Jack Hall, there are no flight services are available on this route on your provided dates.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for contacting us.