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

ASSISTANT: Hello, how can I help you today?

USER: I am planning to visit Nutshell Bike tour in Austin, AUS. Can you help me to book a connecting flight?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My planned journey dates are Apr 28 and 30.

ASSISTANT: Please share me your source point.

USER: My source is from Oakland, OAK.

ASSISTANT: Do you have any specifications?

USER: I want to depart in the afternoon time.

ASSISTANT: Is there any class preference for you?

USER: I am comfortable with any class.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us.