You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I best support you today?

USER: I would like to go from IAD to LAS, can you please help me to book a ticket?

ASSISTANT: Sure, when you want to travel?

USER: My travel dates are from 08/26 to 08/28.

ASSISTANT: Thank you for the details. To proceed for booking we need your name?

USER: My name is Catherine Adams.

ASSISTANT: Thank you for availing with us, unfortunately there are no flights available.

USER: Ok, that's not an issues. Thank you.