You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I planned to meet my friend in HOU, can you please help me to book a flight ticket from IAD?

ASSISTANT: Sure, let me know your travelling dates.

USER: I prefer to travel on Dec 12 and Dec 14.

ASSISTANT: Do you want connecting flight?

USER: I prefer to travel in a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name please?

USER: I am Matthew Roberts.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for opting us.