You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: While checking my recent reservation status I mistakenly cancelled my reservation and again I need booking to DEN from OAK, could you mind help me in booking?

ASSISTANT: Sure, can I know your trip dates please?

USER: My trip dates are from 11/20 to 11/22.

ASSISTANT: Sorry to inform you, there are no flights available as per your request.

USER: That's fine, thank you.

ASSISTANT: Can I know your name please?

USER: Myself Deborah Harris.

ASSISTANT: Thanks.