You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Michelle Thompson. I planned to attend for a meeting in DCA, can you please help me to book a flight ticket from PHL?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: I prefer to travel on 04/28 and 04/30.

ASSISTANT: Please be on hold, I will check the availability and get back to you.

USER: Sure.

ASSISTANT: Sorry to say, no flights were found on your route.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you for your time.