You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be of your assistance?

USER: I am Ruth Perez. I am planning to visit Oakland to enjoy the winter, can you please help me with booking a ticket?

ASSISTANT: Sure, I am glad to help you. Can you please share your journey details for further process?

USER: My preferred journey dates are from 12/11 to 12/13. My airport codes are from DFW to OAK.

ASSISTANT: Ok, please wait a minute.

USER: Ok.

ASSISTANT: Thank you for being patience, no flight found with your details.

USER: May I know the flight details?

ASSISTANT:  There is no flight.

USER: Ok,no issues.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your help.