You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jessica Jackson.

ASSISTANT: How can I serve you?

USER: I need to attend dance competition at Washington, can you please help me to book a flight ticket from OAK to IAD?

ASSISTANT: May I know your journey dates please?

USER: Sure, my trip dates are May 24 and May 26.

ASSISTANT: Is there any class preference?

USER: No, I am comfortable to travel in any class.

ASSISTANT: Please provide your specifications.

USER: I would like to return in the afternoon time.

ASSISTANT: We are sorry to inform you that there is no flight found with your matching information.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you.