You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: This is Ronald Rodriguez.

ASSISTANT: How can I help you for today?

USER: Could you help me for booking a flight ticket from CA-SFO to PA-PHL.

ASSISTANT: Yes, I can help you with your booking. Please let me know the travelling dates?

USER: My departure day is 09/04 and return day is 09/06.

ASSISTANT: Sorry , there are no flights available on 09/04.

USER: Thank you for your service.

ASSISTANT: Thank you for contacting us.