You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am George Clark. I heard that Oakland is a best place for site seeing, can you please book a ticket to OAK?

ASSISTANT: Sure, may I know when would you like to travel?

USER: My depart is on 02/15 and return is on 02/17.

ASSISTANT: From where would you like to board?

USER: Source code is Houston, HOU.

ASSISTANT: Do you need any stopover?

USER: Yes, I need connecting flight.

ASSISTANT: Ok, please wait a moment I will check and revert you.

USER: Sure.

ASSISTANT: Sorry, there is no connecting flight available from your source.

USER: No problem. Thank you.

ASSISTANT: Thank you for opting us.