You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you today?

USER: I am looking to reserve a direct flight from Philadelphia to attend a meeting. Can you please help me to search a flight?

ASSISTANT: Sure, let me know your travelling dates?

USER: Thank you for considering my request. My travel dates are Dec 17 and Dec 19.

ASSISTANT: Please specify your airport codes?

USER: The airports which I prefer to travel are PHL and IAD.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: Thanks for your details, there is no flight found on your journey routes.

USER: It's ok, not a problem with that. Anyways thank you for checking the flight availability.

ASSISTANT: May I know your good name?

USER: My name is Stephen Perez.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.