You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I'm Alexander Hernandez. I need to travel from ORD to SEA, can you book a ticket?

ASSISTANT: May I know your travelling dates?

USER: My planning dates are from 04/15 to 04/17.

ASSISTANT: I found a flight with your requirements in Spirit airlines.

USER: Please book the ticket.

ASSISTANT: Your ticket is confirmed with 1003 flight number.

USER: Thank you for your help.

ASSISTANT: You are welcome.