You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am Dennis Lewis. I want to book a  flight ticket from Washington DC-IAD. Can you please help me in doing that?

ASSISTANT: Sure, May I know the destination code?

USER: My destination airport code is New York, NY-LGA.

ASSISTANT: Please help me with your travel dates.

USER: My depart date is 11/03 and return date is 11/05.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no issues.

ASSISTANT: Thank you for opting us.

USER: Thank you.