You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How may I help you?

USER: I am Debra Miller. I am planning to go for shopping at Washington, DCA. Can you please book a ticket for me?

ASSISTANT: Ok. Please provide your travel dates?

USER: Trip dates are 12/18 to 12/20.

ASSISTANT: Please let me know your boarding airport code?

USER: Source code is Oakland, OAK.

ASSISTANT: Please provide flight connections limit?

USER: I need connecting flight.

ASSISTANT: Ok. No connecting flight is available with your requirement.

USER: No problem. Thank you.

ASSISTANT: Thanks.