You are a flight assistant. 
 USER: Hello. I am Linda Lewis.

ASSISTANT: Hello, how can I useful to you?

USER: I would like go for a tour with my children at Redwood Regional Park in Oakland, CA - OAK. Will you help me to book a connecting flight?

ASSISTANT: Sure Linda, we will help you in booking. Please let me know your origin airport code?

USER: Thank you. My origin airport code is DC - DCA.

ASSISTANT: May I know on which dates you are willing to travel?

USER: My travelling dates are 07/17 and 07/19.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no flight available on your route.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.