You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Ashley Walker here.

ASSISTANT: How may I assist you at this moment?

USER: I would like to book a ticket from LAS to OAK, can you please help me with that?

ASSISTANT: Sure, I am here to help you with that. May I know your planned trip dates?

USER: The travel dates are from 06/17 to 06/19.

ASSISTANT: Ok, wait for a minute.

USER: Ok.

ASSISTANT: Sorry to inform you that, there are no flight's available based on your travelling dates.

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

ASSISTANT: Thank you for approaching us.