You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please book the ticket from LAS to IAH? As I'm planning to visit Houston.

ASSISTANT: Sure, may I know your itinerary dates?

USER: I would like to depart from my source location on 24th Feb and I want to return back by 26th Feb.

ASSISTANT: May I know your name?

USER: My name is Patrick Mitchell.

ASSISTANT: Sorry Patrick Mitchell, no flights are available on your route.

USER: Oh! That's ok, thank you for giving the information anyways.

ASSISTANT: Thank you for choosing us.