You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to book a ticket from PHL to LGA to meet my grandparents, can you help me in booking?

ASSISTANT: Sure, may I know your planned dates to travel?

USER: I am departing on 04/18 and return on 04/20.

ASSISTANT: Sorry for the inconvenience, there is no flight available on your requested dates. May I know your good name please?

USER: That's ok, thank you for your information. My name is Anthony King.

ASSISTANT: Your are welcome.