You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am Ruth Allen, can you help me to book a flight with 200 price?

ASSISTANT: Sure, may I know your travelling dates?

USER: My travelling dates are 12/19 and 12/21.

ASSISTANT: Can you share your airport locations with codes?

USER: My airport codes are SEA and PHL.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: That is fine. Thank you for your time.

ASSISTANT: Thank you for reaching us.