You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am George King. I heard that Houston is a best place for site seeing, Can you please book a ticket to HOU?

ASSISTANT: Please provide your origin airport code.

USER: Source code is Phoenix, PHX.

ASSISTANT: When are you planning to travel?

USER: Travelling dates are 12/24 to 12/26. I need direct flight.

ASSISTANT: Sorry, we found a connecting flight.

USER: Don't proceed. Thank you.

ASSISTANT: Thank you for choosing us.