You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Will you please help me to book a flight from OAK to DEN?

ASSISTANT: Sure, On which dates would you like me to book a flight ticket for you?

USER: My planned dates are on Mar 31st to Apr 2nd.

ASSISTANT: On what name, do I need to reserve your ticket?

USER: Sure, my name is Charles Wilson.

ASSISTANT: Let me know your connection limit?

USER: I prefer a direct flight.

ASSISTANT: Do you have any other requirements?

USER: I would like to return in morning time.

ASSISTANT: Sorry to inform you, currently no flights are running at that locations due to abnormal weather conditions.

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.