You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to visit to DEN, can you book the flight ticket from LAS?

ASSISTANT: Can you please share your travel dates?

USER: My travel dates are from 01/03 till 01/05.

ASSISTANT: May I know your name?

USER: Myself Dorothy Baker.

ASSISTANT: Sorry, no flights are found with your planning dates.

USER: That's ok, no problem. I prefer any other source to reach my destination.

ASSISTANT: Ok, thank you for opting us.

USER: Thank you for your help.

ASSISTANT: Welcome.