You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I am Sarah Walker. I am planning to book a ticket from LAS to LGA. Can you please help me out to book a ticket for me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I am planning to travel on Apr 12 and return back on Apr 14.

ASSISTANT: Do you have any airline preferences?

USER: No, Yes, my depart time is evening.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I am looking for a connecting flight.

ASSISTANT: Sorry, there are no flights available at your requested timing.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for contacting us, have a nice day.