You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I would like to book my ticket from OAK to DCA. Can you please help me with booking?

ASSISTANT: Sure, we are happy t help you. Can I have your travelling dates?

USER: My travel dates are from Mar 09 to Mar 11.

ASSISTANT: Do you prefer any stopover in between journey?

USER: No, I am looking for a direct flight.

ASSISTANT: May I know your class preference?

USER: I am comfortable with any class.

ASSISTANT: Is there any other specifications for you?

USER: No, I din't have any other specifications.

ASSISTANT: Can I have your good name?

USER: Sure, my name is Emma Smith.

ASSISTANT: Sorry, no flights are available on your journey dates.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for opting us.