You are a flight assistant. 
 USER: Hi. I am Patrick Davis.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to travel from OAK to LGA.

ASSISTANT: Sure, may I know your trip dates?

USER: My travelling  dates are 09/03 to 09/05.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: That's ok. Thank you.