You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Jeffery Roberts. I want to travel from Denver, DEN to Boston, BOS to meet my client.

ASSISTANT: May i know your travel dates?

USER: Please book a ticket on 11/26 and 11/28.

ASSISTANT: Do you have any preferences?

USER: I need connecting flight with in 200.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT:  Sorry, no flights are available on your requested dates.

USER: Okay, not a problem.

ASSISTANT:  Thank you for opting us.

USER: Thank you for assisting me.