You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I have planned to book a plane ticket from SFO to LAS, can you assist me?

ASSISTANT: Sure, may I know your travelling dates?

USER: My preferred dates are May 20th and May 22nd.

ASSISTANT: Do you have any connection limit?

USER: I need single connection between my trip.

ASSISTANT: Any other requirements to be met?

USER: I need normal-cost airlines.

ASSISTANT: May I know your good name?

USER: Timothy Walker.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: No problem, thank you for searching.

ASSISTANT: Thank you for reaching us.