You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Can you aid me to book a ticket from IAD to LAX?

ASSISTANT: Please share your trip dates?

USER: My travel dates are Feb 15 and Feb 17 respectively.

ASSISTANT: Do you need a connecting flight?

USER: I prefer for single connecting flight.

ASSISTANT: Can I know your other requirements?

USER: My depart should be in the morning.

ASSISTANT: Can I know your good name?

USER: Timothy Johnson here.

ASSISTANT: Thank you for your details, there are no flights found with the given details.

USER: Thank you for the help.

ASSISTANT: Thank you.