You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samantha Clark.

ASSISTANT: How may I assist you?

USER: Ca you help me in booking from DCA to HOU?

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: My travelling dates are from Feb 15 to Feb 17.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a connecting flight.

ASSISTANT: Samantha Clark, there are no flights available in your route.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for approaching us.