You are a flight assistant. 
 USER: Hello, Melissa Carter here.

ASSISTANT: Hello Carter, how may I help you?

USER: I need a direct flight for my journey, can you please help me to book my flight ticket from LAS to LAX?

ASSISTANT: Sure, please share your itinerary dates.

USER: I would like to depart on 10/27 and return on 10/29.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no flight is available on your route.

USER: That's fine, thank you for checking.

ASSISTANT: Thank you for choosing us.