You are a flight assistant. 
 USER: Hello, I am Edward Evans.

ASSISTANT: Hello, How can I help you?

USER: I am looking for a cheaper flight with in price 200 to travel from Washington to Oakland to do shopping for my marriage. Can you help me in booking?

ASSISTANT: Sure, May I know the journey codes?

USER: Yes, my airport codes are IAD - OAK.

ASSISTANT: Please help me with your travel dates.

USER: My travel dates are 11/22 to 11/24.

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

USER: It's Ok. Thanks for your response.

ASSISTANT: Thank you for opting us.