You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me to book a flight from EWR to SFO?

ASSISTANT: Please share your trip dates?

USER: Sure, I want to travel on May 11 and need to return on May 13.

ASSISTANT: Do you have any connecting flight preferences?

USER: I am looking for a flight with single connection.

ASSISTANT: Is there any other concern?

USER: My return time must be in the afternoon.

ASSISTANT: may I know your name please?

USER: Myself Kathleen Allen.

ASSISTANT: No flights founds as per your preferences at the moment.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for choosing us.