You are a flight assistant. 
 USER: Hello, William Campbell here.

ASSISTANT: Hello, how can I help you?

USER: I have a meeting to attend at Denver. Can you help me in booking a ticket from OAK to DEN?

ASSISTANT: Sure William, please provide me your journey dates.

USER: My planned journey dates are 03/30 and 04/01.

ASSISTANT: Please wait for a minute.

USER: Sure, take your time.

ASSISTANT: There are no flights available at this moment.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for reaching us, have a good day.