You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Good evening. How may I help you?

USER: Good evening. I am planning to attend a automobile workshop in OAK from DFW, can you please book a flight?

ASSISTANT: Sure, When you like to fly please?

USER: I like to fly on the dates of 02/09 and 02/11.

ASSISTANT: May I know your name please?

USER: I am Brandon Harris.

ASSISTANT: There is no flights on your dates Mr.Brandon Harris.

USER: It's ok. Thanks for your valuable information.

ASSISTANT: Thank you for approaching us.