You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I am Andrew Brown. I would like to book a ticket from LAS to IAD, can you please help me out?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can you please share your preferable journey dates?

USER: I am travelling on these dates 02/15 and 02/17.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: I am sorry to say that there is no flight found under your details.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us.