You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to book a flight ticket to meet my best friend in New York EWR from PHL. Can you make a reservation for me?

ASSISTANT: Yes, can you tell me your dates of travel?

USER: Sure, my itinerary dates are on Apr 27 and return on Apr 29.

ASSISTANT: Do you have any preferences?

USER: Ok, I need an economy class.

ASSISTANT: Sorry to inform you that there are no flights found on your requested dates.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Can I know your name?

USER: Yes, I am Sarah Lewis.

ASSISTANT: Thank you for contacting us.

USER: You are welcome.