You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Nicholas Jones here. I want to visit National Zoological Park in Washington DCA. Can you please book my ticket from PHX?

ASSISTANT: When would you like to travel please?

USER: My travelling dates are from 06/13 to 06/15.

ASSISTANT: Sorry, there are no flights available regarding your journey details.

USER: It's ok. Thank you for your time.

ASSISTANT: Thank you and have a nice day.

USER: Thanks.