You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please book me a flight ticket from IAD to IAH to meet my family?

ASSISTANT: Your travelling dates please?

USER: I have planned to travel on June 23rd and return on June 25th.

ASSISTANT: Do you have any connection limit?

USER: I like one connecting flight.

ASSISTANT: Is there any other specifications?

USER: I like economy class.

ASSISTANT: May I know your name please?

USER: William Thompson.

ASSISTANT: I am sorry no flights found on your route.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.