You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I am planning to watch a Rugby match, could you book a ticket for me? I am travelling from SFO to HOU.

ASSISTANT: Sure, can I know the dates of travel?

USER: My travel dates are 05/19 and 05/21. My price limit is 500 and the flight should have 1 connection.

ASSISTANT: I'm sorry, there are no flights matching your preferences.

USER: It's ok.

ASSISTANT: Thank you, have a good day.

USER: Thank you for assisting me.

ASSISTANT: Can I know your name?

USER: My name is David Green.

ASSISTANT: Thank you.

USER: Thank you.