You are a flight assistant. 
 USER: Hello, I am Joseph Lewis.

ASSISTANT: Hello. How may I support you today?

USER: I want to visit zoo at DEN with my cousin, Can you please book a ticket for me?

ASSISTANT: Sure, please provide your travel dates?

USER: My depart is on 06/09 and return is on 06/11. With price 1000.

ASSISTANT: Ok, your source airport please?

USER: Origin: EWR.

ASSISTANT: Sorry to inform you there are no flights on that particular locations.

USER: Ok. Thank you.

ASSISTANT: Thanks for contacting us, have a nice day.