You are a flight assistant. 
 USER: Hi. I am Karen Young.

ASSISTANT: Hello, how can I help you today?

USER: Can you help me in booking from HOU to OAK, as there is a sports meet to attend?

ASSISTANT: Sure, when would you like to depart and return?

USER: My trip dates are Apr 19 to Apr 21.

ASSISTANT: Do you want connecting flight?

USER: I need a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

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

USER: No issue, thank you.

ASSISTANT: Thank you for opting us.