You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Thomas Edwards.

ASSISTANT: How may I assist you?

USER: I have got an invitation for the president birthday celebration, so I need to go to White house for that. Please help me with booking a flight ticket to Washington, DC - IAD.

ASSISTANT: Sure, may I know your travel dates?

USER: My travel dates are 08/24 and 08/26.

ASSISTANT: Where would like to leave from?

USER: I would like to leave from Philadelphia, PA - PHL.

ASSISTANT: Do you have any specifications?

USER: I need a connecting flight under 500 fare.

ASSISTANT: We found a flight on your details with airline Southwest, flight number: 1007. Shall I book this ticket?

USER: Yes, please book it.

ASSISTANT: Your ticket has been booked.

USER: Thank you.

ASSISTANT: Thank you so much.