You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Stephen Allen here. I need to buy a plane ticket from PHL to JFK. Can you help me?

ASSISTANT: Sure, may I know your travelling dates please?

USER: I will start on July 28 and return on July 30.

ASSISTANT: Please provide your specifications.

USER: I need to return in the afternoon.

ASSISTANT: We are sorry to inform you that there is no flight found with your given details.

USER: That's alright, thanks for your assistance.

ASSISTANT: Thank you for availing us.