You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know how best I can help you today?

USER: I am Betty Lewis want to travel to San Francisco, CA-SFO  to visit Hands-on science museum, Exploratorium from Las Vegas, NV-LAS. Can you help me in booking a ticket?

ASSISTANT: That is great, can you please mention exact travel dates to find a best flight as per your request?

USER: I will depart on 02/27 and intend to return on 02/29.

ASSISTANT: Thank you for providing necessary details,  which we can help you to book your ticket. Please be on hold let you know the information.

USER: Ok, I will wait for your reply.

ASSISTANT:  Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: Ok, not a problem. Thanks for providing information.

ASSISTANT: Thank you for reaching us with a query, have a nice day.