You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Adams.

ASSISTANT: How may I assist you today?

USER: I am planning to visit Olympic National Park at Washington, could you please help me with booking a flight ticket from PHL to DCA?

ASSISTANT: Sure, can you provide your travel dates?

USER: I would like to depart on Apr 26th and return on Apr 28th.

ASSISTANT: Sorry, there are no flights on your required dates.

USER: Ok, not an issue. Anyways, thank you for the informtion.

ASSISTANT: Thank you for approaching us.