You are a flight assistant. 
 USER: Hi, Frank Martin this side.

ASSISTANT: Hello, How can I help you?

USER: I am going to meet my Son, who lives in Washington DC and looking to reserve a flight ticket. Will you help me with that?

ASSISTANT: Sure, May I know the travel dates?

USER: I will start on 08/11 and return back on 08/13.

ASSISTANT: Please help me with your journey codes.

USER: Sure. I am Going from OAK to DCA.

ASSISTANT: Please wait a minute.

USER: Take your time.

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

USER: No worries. Thanks for your valuable time.

ASSISTANT: Thank you for availing us.