You are a flight assistant. 
 USER: Hello, I am Paul Walker.

ASSISTANT: Hello. How can I help you?

USER: I would like to leave between 12/12 to 12/14, can you help me to book a ticket?

ASSISTANT: Sure, we are here to help you. Can I know your airport codes?

USER: I would like to travel from OAK to LAX.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT: Thanks for being waiting.

USER: No problem.

ASSISTANT:  Unfortunately,  there is no flight found according to your requriments.

USER: Thank you so much for your service.

ASSISTANT: Thank you for consulting us.