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

ASSISTANT: Hello,. How may I help you?

USER: I want to book a flight ticket from LGA to OAK. Can you book a flight ticket with one connection?

ASSISTANT: Sure. May I know your travelling dates?

USER: I will fly on 01/21 and return on 01/23.

ASSISTANT: Any specifications?

USER: Price limit is 200.

ASSISTANT: I'm sorry, no flights found for your requirement.

USER: Thanks for your response.

ASSISTANT: Thanks.