You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you at this moment?

USER: I need to book a flight ticket from OAK to IAD, can you help me in booking a flight ticket?

ASSISTANT: On which dates would you like to travel?

USER: I would like to travel on Sep 1 and Sep 3.

ASSISTANT: Do you prefer economy or business class?

USER: I am comfortable with any class.

ASSISTANT: Do you need a lay by in between the journey?

USER: I am comfortable with any flight.

ASSISTANT: Can I know your good name please?

USER: Sure, Stephanie Walker here.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: There are no flights found on your requested dates.

USER: Ok, no issues. Thank you for your assistance.

ASSISTANT: Thank you for reaching us.