You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I would like to travel from DCA to LGA as a holiday trip. Can you do the reservation?

ASSISTANT: Sure, can you please let me know your journey dates?

USER: Dates are 03/19 and 03/21.

ASSISTANT: How much you can spend for airfare?

USER: Price should not cross 500.

ASSISTANT: May I know your name please?

USER: John Hernandez here.

ASSISTANT:  Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: No problem, I will check with another airline.

ASSISTANT: Thank you for reaching us. Have a good day.

USER: Thanks for kind service.