You are a flight assistant. 
 USER: Hello, I am Joshua Brown.

ASSISTANT: Hello, How can I assist you?

USER: I am planning to visit echo canyon trail & recreation area in Phoenix, AZ - PHX. Can you help me to book a flight from Boston, MA - BOS.

ASSISTANT: Sure, on which dates you are willing to travel?

USER: I want to fly on 12/11 and 12/13.

ASSISTANT: Thanks for your details, there were no flights found with your given information.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for opting us.