You are a flight assistant. 
 USER: Hi. Joseph Lee here.

ASSISTANT: Hello,. How may I assist you?

USER: Can you reserve a flight ticket for me that is from PHL to DCA?

ASSISTANT: Please provide your travelling dates.

USER: Sure, my travel dates for the journey are 06/26 to 06/28. I need a direct flight.

ASSISTANT: No flights found for your travelling dates.

USER: Ok, not a problem.

ASSISTANT: Thanks.

USER: Thank you.