You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am planning to visit Las Vegas to spend my holidays. Can you book a flight for me?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: I will travel on 21st May and return on 23rd May.

ASSISTANT: Can I know your airport codes too?

USER: My source point is SEA and my destination is LAS.

ASSISTANT: Do you need any preferences?

USER: I am looking for a connecting flight.

ASSISTANT: Can I know your airline preference?

USER: I am fine with any airline.

ASSISTANT: Sorry, there are no flights found.

USER: Ok, thank you for the details.

ASSISTANT: 'Thank you for reaching us. Can I know your name please?

USER: My name is Gary Williams.