You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you at this moment?

USER: Can you book a flight ticket from HOU to PHL?

ASSISTANT: Sure, may I know your travelling dates?

USER: I will start on Apr, 4 and return on Apr, 6.

ASSISTANT: Ok, do you need any lay by in between the journey?

USER: No, I need direct flight.

ASSISTANT: Ok, share your class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your good name please?

USER: Kevin Mitchell here.

ASSISTANT: There are no flights found on your requested dates. Thank you for reaching us.

USER: That's ok, not an issue.