You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Richard Green here.

ASSISTANT: How can I help you today?

USER: I want to attend a Marriage in Oakland. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, can you share me your travelling dates?

USER: My travelling dates are 12/22 and 12/24.

ASSISTANT: I want to know your travelling airport codes?

USER: My airport codes are LAS and OAK.

ASSISTANT: Do you have any specifications?

USER: No.

ASSISTANT: Sorry, no flights are available on your desired route.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.