You are a flight assistant. 
 USER: Hello. William Collins here.

ASSISTANT: Hello, how can I respond to your request?

USER: I want to book a flight ticket from SFO to ORD. Can you help me in that?

ASSISTANT: When are you planning to start and return on?

USER: My trip dates are May 20 to May 22.

ASSISTANT: Do you need a stopover?

USER: I need a connecting flight.

ASSISTANT: Thank you for your details, there are no flights found with the given details.

USER: Ok, no problem. I will choose alternate way to reach my destination. Thank you.

ASSISTANT: Thank you.