You are a flight assistant. 
 USER: Hello, Micheal Collins here.

ASSISTANT: Hello, how can I help you today?

USER: I want to book my flight ticket from Los Angeles to San Francisco.

ASSISTANT: Sure, can you please share your journey dates?

USER: My planned trip dates are May 18-20.

ASSISTANT: Do you have any connection limit?

USER: No, I am comfortable with any connection.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Ok, any other requirements to be met?

USER: I want to depart  in the evening.

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

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thank you for reaching us.