You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Gregory Hall.

ASSISTANT: How can I assist you today?

USER: Can you help me booking flight on 09/01?

ASSISTANT: Sure, please mention your airport codes that you want to travel.

USER: My nearest airport codes are DCA to PHL.

ASSISTANT: Please provide your return date.

USER: I would like to return on 09/03.

ASSISTANT: Please give me a moment. There is no flights available as per your preferable details.

USER: Oh! It's ok, no problem. Thank you for your services.

ASSISTANT: Welcome, have a great day.