You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Jacob Thomas. Please book me a ticket from PHL to DCA to meet my old friends.

ASSISTANT: Sure, can you please share your travel dates?

USER: I have planned to travel on 02/19 and 02/21.

ASSISTANT: Do you have any class preference?

USER: I need a halt.

ASSISTANT: Jacob Thomas, I am sorry to inform you that there is no flight available at your request.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.