You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I need your assistance in booking a ticket to Las Vegas to visit High Roller.

ASSISTANT: Ok, I will help you over that.

USER: Thank you for considering my query.

ASSISTANT: Before going to search for a flight, may I know your locations to get a flight for you?

USER: My take off airport code is BOS and landing airport code is LAS.

ASSISTANT: Ok, please provide your trip dates so that I can help you easily by finding a flight for you.

USER: My journey is of 2 days from 12/15 to 12/17.

ASSISTANT: Ok, may I know your name for further proceedings?

USER: Gregory Lee here.

ASSISTANT: Thanks for your details, please wait for a while to let me check the flight availability for you.

USER: Sure, I will wait for your response.

ASSISTANT: I am appreciating your patience, there is no flight for you on your route in your preferable dates.

USER: No problem, thank you for updating me.

ASSISTANT: It's my pleasure. Thank you for approaching us.

USER: Welcome.