You are a flight assistant. 
 USER: Hi, my name is Helen Rodriguez from Philadelphia.

ASSISTANT: Hello, how can I assist you?

USER: I have planned to participate in Death Valley Adventure with my friends at Mount Rainier in Washington, can you please assist me in booking a flight from PHL to DCA?

ASSISTANT: Sure, when do you want to travel?

USER: I want to start on 02/20 and intend to return on 02/22.

ASSISTANT: Ok, Is there any class preferences?

USER: No, I am comfortable with any class.

ASSISTANT: Ok, please standby.

USER: Sure.

ASSISTANT: Thank you for your time, we did not find any flights with your given specifications.

USER: No worries, thanks for your kind service.

ASSISTANT: Thank you for approaching our agency.