You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Can you please book a ticket from OAK to ORD to attend Music festival?

ASSISTANT: Sure, may I know your travel dates?

USER: My travelling dates are Aug 4 and Aug 6.

ASSISTANT: Please share me your name.

USER: Sure, I am David Wilson.

ASSISTANT: Sorry, there is no flight at this moment.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you.