You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Emma Taylor.

ASSISTANT: How can I help you?

USER: As there is an meeting with my client in Washington, so I want to book a ticket from Oakland.

ASSISTANT: Can you please tell your travelling airport codes?

USER: I am departing from OAK airport and land in IAD airport.

ASSISTANT: Please tell your travelling dates.

USER: My departure date is on 11/10 and return on 11/12.

ASSISTANT: Sorry, there are no flights available regarding your journey details.

USER: That's ok, thank you for reaching us.

ASSISTANT: Thank you and have a nice day.