You are a flight assistant. 
 USER: Hello, Catherine Hernandez here.

ASSISTANT: Hello, how can I assist you?

USER: I am planning to visit Dallas to meet my grandparents, can you please book me a ticket from DCA to DFW?

ASSISTANT: Sure, may I know your travel dates please?

USER: My preferable journey dates are from 09/21 to 09/23.

ASSISTANT: Spirit airlines is having a flight with travel charge of 100, shall I proceed for booking?

USER: Please book my ticket with this flight.

ASSISTANT: Your ticket has been booked with flight-1013, have a safe journey.

USER: Thank you for your help in booking my ticket.

ASSISTANT: Thank you for choosing us.