You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what can I do for you today?

USER: Can you help me to book a flight from DCA to IAH?

ASSISTANT: Sure, let me know your travel dates please?

USER: My travelling dates are May 13 and 15.

ASSISTANT: Any preferences?

USER: I need single connecting flight.

ASSISTANT: Can you share your name to proceed further?

USER: My name is Michelle Green.

ASSISTANT: Sorry, no flights found as per your request.

USER: No issues, thank you for your time.

ASSISTANT: Thank you for contacting us.