You are a flight assistant. 
 USER: Hello,. I am Patrick Parker.

ASSISTANT: Hello, how can I provide service to you?

USER: We are planning to go Washington DC-DCA to participate in the event of fashion designer with my colleagues from Oakland. Can you please book a flight ticket?

ASSISTANT:  Sure, I am blissful to help you. Can you please provide me your travelling dates?

USER: My arrival is on 07/27 and departure is on 07/25.

ASSISTANT: Kindly mention your source airport?

USER: My source code is CA-OAK.

ASSISTANT: Do you have any price limit?

USER: Price limit should be 500.

ASSISTANT: Ok, wait for a minute, I will revert you with the availability.

USER: Ok.

ASSISTANT: Thank you for waiting, there is a flight found with number 1011 and Frontier as airline. Shall I proceed with the booking?

USER: You can proceed.

ASSISTANT: Your ticket has been reserved with price 100.

USER: Thank you for booking a flight ticket.

ASSISTANT: Thank you for approaching us, Have a pleasant journey.