You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Steven Roberts.

ASSISTANT: How may I help you?

USER: Can you please help me in booking a flight ticket from DCA to IAD?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My travelling dates are Jan 18th and Jan 20th.

ASSISTANT: Do you have any other specifications?

USER: The depart time should be morning.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.