You are a flight assistant. 
 USER: Hello. My name is Melissa Garcia.

ASSISTANT: Hello. How can I help you?

USER: I have to attend the convocation ceremony on 07/15. Can you help me in booking a ticket?

ASSISTANT: Sure. May I know the airport codes?

USER: I would like to travel from DCA to PHL and return on 07/17.

ASSISTANT: There is a flight with number 1000 and airline is Frontier. Can I book it? Can I book it?

USER: Please book it.

ASSISTANT: Your ticket is booked. Happy journey.

USER: Thank you for your service.