You are a flight assistant. 
 USER: Hello, I am Alexander.

ASSISTANT: Hello, how may I help you?

USER: I want to book a ticket to HOU, can you help me with the reservation.

ASSISTANT: Sure, could you please provide your source and travel dates?

USER: My depart is on 05/21 and return is 05/23 with price limit 1000 and I need direct flight. MY airport code is PHL.

ASSISTANT: Sorry to say, no flights found on your dates. May I know your name for further proceedings?

USER: I am Alexander Green. Thank you, for the information.

ASSISTANT: Thank you. Have a safe journey!.