You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you the best today?

USER: Could you please book a flight ticket from PHL to EWR?

ASSISTANT: Sure, On which dates would you like me to book a flight ticket for you?

USER: I want to travel on May 21 and return on May 23.

ASSISTANT: On what name, do I need to reserve the ticket?

USER: My name is Janet Nelson.

ASSISTANT: Do you have any other restrictions to be met?

USER: No.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: No problem, thank you.

ASSISTANT: Thank you for approaching us.