You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Kenneth Thompson. I want to travel from SFO to HOU. Can you book a flight ticket for me?

ASSISTANT: Sure, may I know your travel dates?

USER: I want to fly in the flight on May 19 and May 21.

ASSISTANT: At what time do you like to travel?

USER: I want to return in evening time.

ASSISTANT: Do you prefer economy or business class?

USER: No, but I want to have a connection of 1.

ASSISTANT: I am sorry to inform you there is no flight on your route.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you.