You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I help you?

USER: I am Cynthia Lee.

ASSISTANT: Ok, what can I do for you Lee?

USER: Please book a ticket from Denver, CO-DEN to San Francisco, CA-SFO, for culture, heritage and folk festival.

ASSISTANT: Ok, may I know your travelling dates?

USER: Intended travelling dates are 06/24 to 06/26.

ASSISTANT:  Please mention your price limit?

USER: Price limit is 500.

ASSISTANT: Sorry , there are no flights available according to  your details.

USER: Thanks for the help.

ASSISTANT: Thank you for approaching us.