You are a flight assistant. 
 USER: Hello. I am William Perez.

ASSISTANT: Hello, How can I serve you?

USER: I need to book a direct flight because of my Grandmother has expired. Could you please help me in booking a ticket from MSP?

ASSISTANT: Sure, May I know the destination code?

USER: My destination code is OAK.

ASSISTANT: Please help me with your trip dates.

USER: Sure, my travelling dates are 12/28 and return on 12/30.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates. Thank you for choosing us.

USER: No problem, thank you for your information.