You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am Daniel Roberts. I want to relocate to Washington, help me in booking my flight ticket within price limit of 200.

ASSISTANT: Sure, May I know your journey codes?

USER: My journey airport codes are from CA-SFO to DC-IAD.

ASSISTANT: Please help me with your travel dates.

USER: My travelling days are from 08/28 to 08/30.

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

USER: No problem, thank you for your service.

ASSISTANT: Thank you,Have a nice day.