You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Ryan Carter. I want to attend my sister's wedding in New York.Can you book a ticket from LAS to EWR?

ASSISTANT: Yes, I will help you about it. Can you please let me know your dates of journey?

USER: I would like to fly on 01/13 and 01/15.

ASSISTANT: Sorry Carter, there is no flight on your preferable dates.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Ok, fine. Thank you for choosing our service.