You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, How can I help you?

USER: I want to visit my grandmother home for a vacation, can you help me in booking a ticket?

ASSISTANT: Sure, May I know the details of your journey?

USER: I want to start my vacation on 01/06 and end on 01/08.

ASSISTANT: May I know the airport abbreviates?

USER: Airport codes are from Houston,TX- IAH to  Oakland,CA-OAK. Please ensure that I need a direct fligt.

ASSISTANT: Sorry to tell that there is no flight found according to your details.

USER: Thank you  for the information.

ASSISTANT: May I know your name?

USER: I am Jacob Anderson.

ASSISTANT: Thank you.