You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Stephen Taylor here. Can you book a flight ticket from DCA to OAK?

ASSISTANT: Sure, could you please share me with your dates of journey?

USER: My travelling dates are 10/26 and 10/28.

ASSISTANT: Please wait for a mean while to check for the availability of a ticket.

USER: Ok, carry on.

ASSISTANT: Sorry Taylor, there is no flight found as per your travelling details.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for choosing us and hope you will meet us again.