You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Margaret Lopez. I would like to attend Environmental Science Conferences in Lawrence Hall of Science at Oakland, OAK. Please help me with a connecting flight.

ASSISTANT: Sure, On what dates you wish to travel?

USER: My preferred travelling dates are from 09/19 to 09/21.

ASSISTANT: Where do you want to start your journey from?

USER: I want to fly from SEA to OAK.

ASSISTANT: Sorry, there are no flights with your requirement.

USER: No issues, thank you.

ASSISTANT: Have a good day.